diff --git a/CHANGELOG.md b/CHANGELOG.md
index fcd4ca4f..36b1b552 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,72 @@ To see unreleased changes, please see the [CHANGELOG on the main branch guide](h
 
 <!-- towncrier release notes start -->
 
+## [0.21.0-beta.0] - 2024-03-10
+
+### Added
+
+- Add `PyMemoryView` type. [#3514](https://github.com/PyO3/pyo3/pull/3514)
+- Support `async fn` in macros with coroutine implementation [#3540](https://github.com/PyO3/pyo3/pull/3540)
+- Implement `PyTypeInfo` for `PyEllipsis`, `PyNone` and `PyNotImplemented`. [#3577](https://github.com/PyO3/pyo3/pull/3577)
+- Support `#[pyclass]` on enums that have non-unit variants. [#3582](https://github.com/PyO3/pyo3/pull/3582)
+- Add `__name__`/`__qualname__` attributes to `Coroutine` [#3588](https://github.com/PyO3/pyo3/pull/3588)
+- Add `coroutine::CancelHandle` to catch coroutine cancellation [#3599](https://github.com/PyO3/pyo3/pull/3599)
+- Add support for extracting Rust set types from `frozenset`. [#3632](https://github.com/PyO3/pyo3/pull/3632)
+- `FromPyObject`, `IntoPy<PyObject>` and `ToPyObject` are implemented on `std::duration::Duration` [#3670](https://github.com/PyO3/pyo3/pull/3670)
+- Add `PyString::to_cow`. Add `Py<PyString>::to_str`, `Py<PyString>::to_cow`, and `Py<PyString>::to_string_lossy`, as ways to access Python string data safely beyond the GIL lifetime. [#3677](https://github.com/PyO3/pyo3/pull/3677)
+- Add `Bound<T>` and `Borrowed<T>` smart pointers as a new API for accessing Python objects. [#3686](https://github.com/PyO3/pyo3/pull/3686)
+- Add `PyNativeType::as_bound` to convert "GIL refs" to the new `Bound` smart pointer. [#3692](https://github.com/PyO3/pyo3/pull/3692)
+- Add `FromPyObject::extract_bound` method, which can be implemented to avoid using the GIL Ref API in `FromPyObject` implementations. [#3706](https://github.com/PyO3/pyo3/pull/3706)
+- Add `gil-refs` feature to allow continued use of the deprecated GIL Refs APIs. [#3707](https://github.com/PyO3/pyo3/pull/3707)
+- Added methods to `PyAnyMethods` for binary operators (`add`, `sub`, etc.) [#3712](https://github.com/PyO3/pyo3/pull/3712)
+- `chrono-tz` feature allowing conversion between `chrono_tz::Tz` and `zoneinfo.ZoneInfo` [#3730](https://github.com/PyO3/pyo3/pull/3730)
+- Add definition for `PyType_GetModuleByDef` to `pyo3_ffi`. [#3734](https://github.com/PyO3/pyo3/pull/3734)
+- Conversion between `std::time::SystemTime` and `datetime.datetime` [#3736](https://github.com/PyO3/pyo3/pull/3736)
+- Add `Py::as_any` and `Py::into_any`. [#3785](https://github.com/PyO3/pyo3/pull/3785)
+- Add `PyStringMethods::encode_utf8`. [#3801](https://github.com/PyO3/pyo3/pull/3801)
+- Add `PyBackedStr` and `PyBackedBytes`, as alternatives to `&str` and `&bytes` where a Python object owns the data. [#3802](https://github.com/PyO3/pyo3/pull/3802)
+- The ability to create Python modules with a Rust `mod` block
+  behind the `experimental-declarative-modules` feature. [#3815](https://github.com/PyO3/pyo3/pull/3815)
+- Implement `ExactSizeIterator` for `set` and `frozenset` iterators on `abi3` feature. [#3849](https://github.com/PyO3/pyo3/pull/3849)
+- Add `Py::drop_ref` to explicitly drop a `Py`` and immediately decrease the Python reference count if the GIL is already held. [#3871](https://github.com/PyO3/pyo3/pull/3871)
+- Implement `FromPyObject` for `Cow<str>`. [#3928](https://github.com/PyO3/pyo3/pull/3928)
+- Add `experimental-async` feature. [#3931](https://github.com/PyO3/pyo3/pull/3931)
+
+### Changed
+
+- - `PyDict::from_sequence` now takes a single argument of type `&PyAny` (previously took two arguments `Python` and `PyObject`). [#3532](https://github.com/PyO3/pyo3/pull/3532)
+- Deprecate `Py::is_ellipsis` and `PyAny::is_ellipsis` in favour of `any.is(py.Ellipsis())`. [#3577](https://github.com/PyO3/pyo3/pull/3577)
+- Split some `PyTypeInfo` functionality into new traits `HasPyGilRef` and `PyTypeCheck`. [#3600](https://github.com/PyO3/pyo3/pull/3600)
+- Deprecate `PyTryFrom` and `PyTryInto` traits in favor of `any.downcast()` via the `PyTypeCheck` and `PyTypeInfo` traits. [#3601](https://github.com/PyO3/pyo3/pull/3601)
+- Allow async methods to accept `&self`/`&mut self` [#3609](https://github.com/PyO3/pyo3/pull/3609)
+- Values of type `bool` can now be extracted from NumPy's `bool_`. [#3638](https://github.com/PyO3/pyo3/pull/3638)
+- Add `AsRefSource` to `PyNativeType`. [#3653](https://github.com/PyO3/pyo3/pull/3653)
+- Changed `.is_true` to `.is_truthy` on `PyAny` and `Py<PyAny>` to clarify that the test is not based on identity with or equality to the True singleton. [#3657](https://github.com/PyO3/pyo3/pull/3657)
+- `PyType::name` is now `PyType::qualname` whereas `PyType::name` efficiently accesses the full name which includes the module name. [#3660](https://github.com/PyO3/pyo3/pull/3660)
+- The `Iter(A)NextOutput` types are now deprecated and `__(a)next__` can directly return anything which can be converted into Python objects, i.e. awaitables do not need to be wrapped into `IterANextOutput` or `Option` any more. `Option` can still be used as well and returning `None` will trigger the fast path for `__next__`, stopping iteration without having to raise a `StopIteration` exception. [#3661](https://github.com/PyO3/pyo3/pull/3661)
+- Implements `FromPyObject` on `chrono::DateTime<Tz>` for all `Tz` and not only `FixedOffset` and `Utc` [#3663](https://github.com/PyO3/pyo3/pull/3663)
+- `chrono` conversions are compatible with `abi3` [#3664](https://github.com/PyO3/pyo3/pull/3664)
+- Add lifetime parameter to `PyTzInfoAccess` trait. For the deprecated gil-ref API, the trait is now implemented for `&'py PyTime` and `&'py PyDateTime` instead of `PyTime` and `PyDate`. [#3679](https://github.com/PyO3/pyo3/pull/3679)
+- Calls to `__traverse__` become no-ops for unsendable pyclasses if on the wrong thread, thereby avoiding hard aborts at the cost of potential leakage. [#3689](https://github.com/PyO3/pyo3/pull/3689)
+- Include `PyNativeType` in `pyo3::prelude`. [#3692](https://github.com/PyO3/pyo3/pull/3692)
+- Improve performance of `extract::<i64>` (and other integer types) by avoiding call to `__index__()` converting the value to an integer for 3.10+. Gives performance improvement of around 30% for successful extraction. [#3742](https://github.com/PyO3/pyo3/pull/3742)
+- Relax bound of `FromPyObject` for `Py<T>` to just `T: PyTypeCheck`. [#3776](https://github.com/PyO3/pyo3/pull/3776)
+- `PySet` and `PyFrozenSet` iterators now always iterate the equivalent of `iter(set)`. (A "fast path" with no noticeable performance benefit was removed.) [#3849](https://github.com/PyO3/pyo3/pull/3849)
+- The `#[pymodule]` macro now supports module functions that take a single argument as a `&Bound<'_, PyModule>`. [#3905](https://github.com/PyO3/pyo3/pull/3905)
+- Move implementations of `FromPyObject` for `&str`, `Cow<str>`, `&[u8]` and `Cow<[u8]>` onto a temporary trait `FromPyObjectBound` when `gil-refs` feature is deactivated. [#3928](https://github.com/PyO3/pyo3/pull/3928)
+
+### Removed
+
+- Remove all functionality deprecated in PyO3 0.19. [#3603](https://github.com/PyO3/pyo3/pull/3603)
+- Remove `PyCode` and `PyCode_Type` on PyPy: `PyCode_Type` is not exposed by PyPy. [#3934](https://github.com/PyO3/pyo3/pull/3934)
+
+### Fixed
+
+- Match PyPy 7.3.14 in removing PyPy-only symbol `Py_MAX_NDIMS` in favour of `PyBUF_MAX_NDIM`. [#3757](https://github.com/PyO3/pyo3/pull/3757)
+- Fix segmentation fault using `datetime` types when an invalid `datetime` module is on sys.path. [#3818](https://github.com/PyO3/pyo3/pull/3818)
+- Fix `non_local_definitions` lint warning triggered by many PyO3 macros. [#3901](https://github.com/PyO3/pyo3/pull/3901)
+
+
 ## [0.20.3] - 2024-02-23
 
 ### Packaging
@@ -1640,7 +1706,7 @@ Yanked
 
 - Initial release
 
-[Unreleased]: https://github.com/pyo3/pyo3/compare/v0.20.3...HEAD
+[0.21.0-beta.0]: https://github.com/pyo3/pyo3/compare/v0.20.3...v0.21.0-beta.0
 [0.20.3]: https://github.com/pyo3/pyo3/compare/v0.20.2...v0.20.3
 [0.20.2]: https://github.com/pyo3/pyo3/compare/v0.20.1...v0.20.2
 [0.20.1]: https://github.com/pyo3/pyo3/compare/v0.20.0...v0.20.1
diff --git a/Cargo.toml b/Cargo.toml
index 32dc0ba7..ba5c3461 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pyo3"
-version = "0.21.0-dev"
+version = "0.21.0-beta.0"
 description = "Bindings to Python interpreter"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 readme = "README.md"
@@ -22,10 +22,10 @@ memoffset = "0.9"
 portable-atomic = "1.0"
 
 # ffi bindings to the python interpreter, split into a separate crate so they can be used independently
-pyo3-ffi = { path = "pyo3-ffi", version = "=0.21.0-dev" }
+pyo3-ffi = { path = "pyo3-ffi", version = "=0.21.0-beta.0" }
 
 # support crates for macros feature
-pyo3-macros = { path = "pyo3-macros", version = "=0.21.0-dev", optional = true }
+pyo3-macros = { path = "pyo3-macros", version = "=0.21.0-beta.0", optional = true }
 indoc = { version = "2.0.1", optional = true }
 unindent = { version = "0.2.1", optional = true }
 
@@ -60,7 +60,7 @@ rayon = "1.6.1"
 futures = "0.3.28"
 
 [build-dependencies]
-pyo3-build-config = { path = "pyo3-build-config", version = "=0.21.0-dev", features = ["resolve-config"] }
+pyo3-build-config = { path = "pyo3-build-config", version = "=0.21.0-beta.0", features = ["resolve-config"] }
 
 [features]
 default = ["macros"]
diff --git a/newsfragments/3514.added.md b/newsfragments/3514.added.md
deleted file mode 100644
index 7fbf662b..00000000
--- a/newsfragments/3514.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `PyMemoryView` type.
diff --git a/newsfragments/3532.changed.md b/newsfragments/3532.changed.md
deleted file mode 100644
index b65f2409..00000000
--- a/newsfragments/3532.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-- `PyDict::from_sequence` now takes a single argument of type `&PyAny` (previously took two arguments `Python` and `PyObject`).
diff --git a/newsfragments/3540.added.md b/newsfragments/3540.added.md
deleted file mode 100644
index 2b113193..00000000
--- a/newsfragments/3540.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Support `async fn` in macros with coroutine implementation
\ No newline at end of file
diff --git a/newsfragments/3577.added.md b/newsfragments/3577.added.md
deleted file mode 100644
index 63227498..00000000
--- a/newsfragments/3577.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Implement `PyTypeInfo` for `PyEllipsis`, `PyNone` and `PyNotImplemented`.
diff --git a/newsfragments/3577.changed.md b/newsfragments/3577.changed.md
deleted file mode 100644
index a7e6629d..00000000
--- a/newsfragments/3577.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Deprecate `Py::is_ellipsis` and `PyAny::is_ellipsis` in favour of `any.is(py.Ellipsis())`.
diff --git a/newsfragments/3582.added.md b/newsfragments/3582.added.md
deleted file mode 100644
index 59659a88..00000000
--- a/newsfragments/3582.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Support `#[pyclass]` on enums that have non-unit variants.
diff --git a/newsfragments/3588.added.md b/newsfragments/3588.added.md
deleted file mode 100644
index acddf296..00000000
--- a/newsfragments/3588.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `__name__`/`__qualname__` attributes to `Coroutine`
\ No newline at end of file
diff --git a/newsfragments/3599.added.md b/newsfragments/3599.added.md
deleted file mode 100644
index 36078fbc..00000000
--- a/newsfragments/3599.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `coroutine::CancelHandle` to catch coroutine cancellation
\ No newline at end of file
diff --git a/newsfragments/3600.changed.md b/newsfragments/3600.changed.md
deleted file mode 100644
index c8701ef4..00000000
--- a/newsfragments/3600.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Split some `PyTypeInfo` functionality into new traits `HasPyGilRef` and `PyTypeCheck`.
diff --git a/newsfragments/3601.changed.md b/newsfragments/3601.changed.md
deleted file mode 100644
index 413765ec..00000000
--- a/newsfragments/3601.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Deprecate `PyTryFrom` and `PyTryInto` traits in favor of `any.downcast()` via the `PyTypeCheck` and `PyTypeInfo` traits.
diff --git a/newsfragments/3603.removed.md b/newsfragments/3603.removed.md
deleted file mode 100644
index e8f5004e..00000000
--- a/newsfragments/3603.removed.md
+++ /dev/null
@@ -1 +0,0 @@
-Remove all functionality deprecated in PyO3 0.19.
diff --git a/newsfragments/3609.changed.md b/newsfragments/3609.changed.md
deleted file mode 100644
index 7979ea71..00000000
--- a/newsfragments/3609.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Allow async methods to accept `&self`/`&mut self`
\ No newline at end of file
diff --git a/newsfragments/3632.added.md b/newsfragments/3632.added.md
deleted file mode 100644
index d9c954fa..00000000
--- a/newsfragments/3632.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add support for extracting Rust set types from `frozenset`.
diff --git a/newsfragments/3638.changed.md b/newsfragments/3638.changed.md
deleted file mode 100644
index 6bdafde8..00000000
--- a/newsfragments/3638.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Values of type `bool` can now be extracted from NumPy's `bool_`.
diff --git a/newsfragments/3653.changed.md b/newsfragments/3653.changed.md
deleted file mode 100644
index 75fea03c..00000000
--- a/newsfragments/3653.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `AsRefSource` to `PyNativeType`.
diff --git a/newsfragments/3657.changed.md b/newsfragments/3657.changed.md
deleted file mode 100644
index 0a519b09..00000000
--- a/newsfragments/3657.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Changed `.is_true` to `.is_truthy` on `PyAny` and `Py<PyAny>` to clarify that the test is not based on identity with or equality to the True singleton.
diff --git a/newsfragments/3660.changed.md b/newsfragments/3660.changed.md
deleted file mode 100644
index 8b4a3f73..00000000
--- a/newsfragments/3660.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-`PyType::name` is now `PyType::qualname` whereas `PyType::name` efficiently accesses the full name which includes the module name.
diff --git a/newsfragments/3661.changed.md b/newsfragments/3661.changed.md
deleted file mode 100644
index 8245a6f1..00000000
--- a/newsfragments/3661.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-The `Iter(A)NextOutput` types are now deprecated and `__(a)next__` can directly return anything which can be converted into Python objects, i.e. awaitables do not need to be wrapped into `IterANextOutput` or `Option` any more. `Option` can still be used as well and returning `None` will trigger the fast path for `__next__`, stopping iteration without having to raise a `StopIteration` exception.
diff --git a/newsfragments/3663.changed.md b/newsfragments/3663.changed.md
deleted file mode 100644
index 13c07e01..00000000
--- a/newsfragments/3663.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Implements `FromPyObject` on `chrono::DateTime<Tz>` for all `Tz` and not only `FixedOffset` and `Utc`
\ No newline at end of file
diff --git a/newsfragments/3664.changed.md b/newsfragments/3664.changed.md
deleted file mode 100644
index 3a167d2f..00000000
--- a/newsfragments/3664.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-`chrono` conversions are compatible with `abi3`
\ No newline at end of file
diff --git a/newsfragments/3670.added.md b/newsfragments/3670.added.md
deleted file mode 100644
index a524261e..00000000
--- a/newsfragments/3670.added.md
+++ /dev/null
@@ -1 +0,0 @@
-`FromPyObject`, `IntoPy<PyObject>` and `ToPyObject` are implemented on `std::duration::Duration`
\ No newline at end of file
diff --git a/newsfragments/3677.added.md b/newsfragments/3677.added.md
deleted file mode 100644
index 3e6bc56d..00000000
--- a/newsfragments/3677.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `PyString::to_cow`. Add `Py<PyString>::to_str`, `Py<PyString>::to_cow`, and `Py<PyString>::to_string_lossy`, as ways to access Python string data safely beyond the GIL lifetime.
diff --git a/newsfragments/3679.changed.md b/newsfragments/3679.changed.md
deleted file mode 100644
index ab46598a..00000000
--- a/newsfragments/3679.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Add lifetime parameter to `PyTzInfoAccess` trait. For the deprecated gil-ref API, the trait is now implemented for `&'py PyTime` and `&'py PyDateTime` instead of `PyTime` and `PyDate`.
diff --git a/newsfragments/3686.added.md b/newsfragments/3686.added.md
deleted file mode 100644
index f808df36..00000000
--- a/newsfragments/3686.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `Bound<T>` and `Borrowed<T>` smart pointers as a new API for accessing Python objects.
diff --git a/newsfragments/3689.changed.md b/newsfragments/3689.changed.md
deleted file mode 100644
index 30928e82..00000000
--- a/newsfragments/3689.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Calls to `__traverse__` become no-ops for unsendable pyclasses if on the wrong thread, thereby avoiding hard aborts at the cost of potential leakage.
diff --git a/newsfragments/3692.added.md b/newsfragments/3692.added.md
deleted file mode 100644
index 45cdd5ab..00000000
--- a/newsfragments/3692.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `PyNativeType::as_bound` to convert "GIL refs" to the new `Bound` smart pointer.
diff --git a/newsfragments/3692.changed.md b/newsfragments/3692.changed.md
deleted file mode 100644
index 9535cbb2..00000000
--- a/newsfragments/3692.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Include `PyNativeType` in `pyo3::prelude`.
diff --git a/newsfragments/3706.added.md b/newsfragments/3706.added.md
deleted file mode 100644
index 31db8b96..00000000
--- a/newsfragments/3706.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `FromPyObject::extract_bound` method, which can be implemented to avoid using the GIL Ref API in `FromPyObject` implementations.
diff --git a/newsfragments/3707.added.md b/newsfragments/3707.added.md
deleted file mode 100644
index bc92e2c0..00000000
--- a/newsfragments/3707.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `gil-refs` feature to allow continued use of the deprecated GIL Refs APIs.
diff --git a/newsfragments/3712.added.md b/newsfragments/3712.added.md
deleted file mode 100644
index d7390f77..00000000
--- a/newsfragments/3712.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Added methods to `PyAnyMethods` for binary operators (`add`, `sub`, etc.)
diff --git a/newsfragments/3730.added.md b/newsfragments/3730.added.md
deleted file mode 100644
index 7e287245..00000000
--- a/newsfragments/3730.added.md
+++ /dev/null
@@ -1 +0,0 @@
-`chrono-tz` feature allowing conversion between `chrono_tz::Tz` and `zoneinfo.ZoneInfo`
\ No newline at end of file
diff --git a/newsfragments/3734.added.md b/newsfragments/3734.added.md
deleted file mode 100644
index e58c2038..00000000
--- a/newsfragments/3734.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add definition for `PyType_GetModuleByDef` to `pyo3_ffi`.
diff --git a/newsfragments/3736.added.md b/newsfragments/3736.added.md
deleted file mode 100644
index 0d3a4a08..00000000
--- a/newsfragments/3736.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Conversion between `std::time::SystemTime` and `datetime.datetime`
\ No newline at end of file
diff --git a/newsfragments/3742.changed.md b/newsfragments/3742.changed.md
deleted file mode 100644
index b8805aba..00000000
--- a/newsfragments/3742.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Improve performance of `extract::<i64>` (and other integer types) by avoiding call to `__index__()` converting the value to an integer for 3.10+. Gives performance improvement of around 30% for successful extraction.
diff --git a/newsfragments/3757.fixed.md b/newsfragments/3757.fixed.md
deleted file mode 100644
index 103a634a..00000000
--- a/newsfragments/3757.fixed.md
+++ /dev/null
@@ -1 +0,0 @@
-Match PyPy 7.3.14 in removing PyPy-only symbol `Py_MAX_NDIMS` in favour of `PyBUF_MAX_NDIM`.
diff --git a/newsfragments/3776.changed.md b/newsfragments/3776.changed.md
deleted file mode 100644
index 71ffd893..00000000
--- a/newsfragments/3776.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Relax bound of `FromPyObject` for `Py<T>` to just `T: PyTypeCheck`.
diff --git a/newsfragments/3785.added.md b/newsfragments/3785.added.md
deleted file mode 100644
index 6af3bb99..00000000
--- a/newsfragments/3785.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `Py::as_any` and `Py::into_any`.
diff --git a/newsfragments/3801.added.md b/newsfragments/3801.added.md
deleted file mode 100644
index 78f45032..00000000
--- a/newsfragments/3801.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `PyStringMethods::encode_utf8`.
diff --git a/newsfragments/3802.added.md b/newsfragments/3802.added.md
deleted file mode 100644
index 86b98e9d..00000000
--- a/newsfragments/3802.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `PyBackedStr` and `PyBackedBytes`, as alternatives to `&str` and `&bytes` where a Python object owns the data.
diff --git a/newsfragments/3815.added.md b/newsfragments/3815.added.md
deleted file mode 100644
index e4fd3e93..00000000
--- a/newsfragments/3815.added.md
+++ /dev/null
@@ -1,2 +0,0 @@
-The ability to create Python modules with a Rust `mod` block
-behind the `experimental-declarative-modules` feature.
\ No newline at end of file
diff --git a/newsfragments/3818.fixed.md b/newsfragments/3818.fixed.md
deleted file mode 100644
index 76fe01a5..00000000
--- a/newsfragments/3818.fixed.md
+++ /dev/null
@@ -1 +0,0 @@
-Fix segmentation fault using `datetime` types when an invalid `datetime` module is on sys.path.
diff --git a/newsfragments/3849.added.md b/newsfragments/3849.added.md
deleted file mode 100644
index 8aa9a55d..00000000
--- a/newsfragments/3849.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Implement `ExactSizeIterator` for `set` and `frozenset` iterators on `abi3` feature.
diff --git a/newsfragments/3849.changed.md b/newsfragments/3849.changed.md
deleted file mode 100644
index ee8dfbf5..00000000
--- a/newsfragments/3849.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-`PySet` and `PyFrozenSet` iterators now always iterate the equivalent of `iter(set)`. (A "fast path" with no noticeable performance benefit was removed.)
diff --git a/newsfragments/3871.added.md b/newsfragments/3871.added.md
deleted file mode 100644
index f90e92fd..00000000
--- a/newsfragments/3871.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `Py::drop_ref` to explicitly drop a `Py`` and immediately decrease the Python reference count if the GIL is already held.
diff --git a/newsfragments/3901.fixed.md b/newsfragments/3901.fixed.md
deleted file mode 100644
index 0845c2bb..00000000
--- a/newsfragments/3901.fixed.md
+++ /dev/null
@@ -1 +0,0 @@
-Fix `non_local_definitions` lint warning triggered by many PyO3 macros.
diff --git a/newsfragments/3905.changed.md b/newsfragments/3905.changed.md
deleted file mode 100644
index 917584eb..00000000
--- a/newsfragments/3905.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-The `#[pymodule]` macro now supports module functions that take a single argument as a `&Bound<'_, PyModule>`.
diff --git a/newsfragments/3928.added.md b/newsfragments/3928.added.md
deleted file mode 100644
index e768e6b0..00000000
--- a/newsfragments/3928.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Implement `FromPyObject` for `Cow<str>`.
diff --git a/newsfragments/3928.changed.md b/newsfragments/3928.changed.md
deleted file mode 100644
index a4734c41..00000000
--- a/newsfragments/3928.changed.md
+++ /dev/null
@@ -1 +0,0 @@
-Move implementations of `FromPyObject` for `&str`, `Cow<str>`, `&[u8]` and `Cow<[u8]>` onto a temporary trait `FromPyObjectBound` when `gil-refs` feature is deactivated.
diff --git a/newsfragments/3931.added.md b/newsfragments/3931.added.md
deleted file mode 100644
index b532adee..00000000
--- a/newsfragments/3931.added.md
+++ /dev/null
@@ -1 +0,0 @@
-Add `experimental-async` feature.
diff --git a/newsfragments/3934.removed.md b/newsfragments/3934.removed.md
deleted file mode 100644
index 66741d3f..00000000
--- a/newsfragments/3934.removed.md
+++ /dev/null
@@ -1 +0,0 @@
-Remove `PyCode` and `PyCode_Type` on PyPy: `PyCode_Type` is not exposed by PyPy.
\ No newline at end of file
diff --git a/pyo3-build-config/Cargo.toml b/pyo3-build-config/Cargo.toml
index 702e99a4..c00427eb 100644
--- a/pyo3-build-config/Cargo.toml
+++ b/pyo3-build-config/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pyo3-build-config"
-version = "0.21.0-dev"
+version = "0.21.0-beta.0"
 description = "Build configuration for the PyO3 ecosystem"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 keywords = ["pyo3", "python", "cpython", "ffi"]
diff --git a/pyo3-ffi/Cargo.toml b/pyo3-ffi/Cargo.toml
index 8021dc72..8dea584e 100644
--- a/pyo3-ffi/Cargo.toml
+++ b/pyo3-ffi/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pyo3-ffi"
-version = "0.21.0-dev"
+version = "0.21.0-beta.0"
 description = "Python-API bindings for the PyO3 ecosystem"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 keywords = ["pyo3", "python", "cpython", "ffi"]
@@ -38,7 +38,7 @@ abi3-py312 = ["abi3", "pyo3-build-config/abi3-py312"]
 generate-import-lib = ["pyo3-build-config/python3-dll-a"]
 
 [build-dependencies]
-pyo3-build-config = { path = "../pyo3-build-config", version = "=0.21.0-dev", features = ["resolve-config"] }
+pyo3-build-config = { path = "../pyo3-build-config", version = "=0.21.0-beta.0", features = ["resolve-config"] }
 
 [lints]
 workspace = true
diff --git a/pyo3-macros-backend/Cargo.toml b/pyo3-macros-backend/Cargo.toml
index 665c8c35..abf71902 100644
--- a/pyo3-macros-backend/Cargo.toml
+++ b/pyo3-macros-backend/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pyo3-macros-backend"
-version = "0.21.0-dev"
+version = "0.21.0-beta.0"
 description = "Code generation for PyO3 package"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 keywords = ["pyo3", "python", "cpython", "ffi"]
@@ -16,7 +16,7 @@ edition = "2021"
 [dependencies]
 heck = "0.4"
 proc-macro2 = { version = "1", default-features = false }
-pyo3-build-config = { path = "../pyo3-build-config", version = "=0.21.0-dev", features = ["resolve-config"] }
+pyo3-build-config = { path = "../pyo3-build-config", version = "=0.21.0-beta.0", features = ["resolve-config"] }
 quote = { version = "1", default-features = false }
 
 [dependencies.syn]
diff --git a/pyo3-macros/Cargo.toml b/pyo3-macros/Cargo.toml
index 97d2de07..008224e7 100644
--- a/pyo3-macros/Cargo.toml
+++ b/pyo3-macros/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pyo3-macros"
-version = "0.21.0-dev"
+version = "0.21.0-beta.0"
 description = "Proc macros for PyO3 package"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 keywords = ["pyo3", "python", "cpython", "ffi"]
@@ -22,7 +22,7 @@ experimental-declarative-modules = []
 proc-macro2 = { version = "1", default-features = false }
 quote = "1"
 syn = { version = "2", features = ["full", "extra-traits"] }
-pyo3-macros-backend = { path = "../pyo3-macros-backend", version = "=0.21.0-dev" }
+pyo3-macros-backend = { path = "../pyo3-macros-backend", version = "=0.21.0-beta.0" }
 
 [lints]
 workspace = true
diff --git a/pyproject.toml b/pyproject.toml
index 866645d2..5d5ef42b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -3,7 +3,7 @@
 
 [tool.towncrier]
 filename = "CHANGELOG.md"
-version = "0.21.0-dev"
+version = "0.21.0-beta.0"
 start_string = "<!-- towncrier release notes start -->\n"
 template = ".towncrier.template.md"
 title_format = "## [{version}] - {project_date}"