diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index ce7cf1ac124..e96de66ac76 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -40,7 +40,7 @@ env:
   CACHE_VERSION: 4
   UV_CACHE_VERSION: 1
   MYPY_CACHE_VERSION: 1
-  HA_SHORT_VERSION: "2025.8"
+  HA_SHORT_VERSION: "2025.9"
   DEFAULT_PYTHON: "3.13"
   ALL_PYTHON_VERSIONS: "['3.13']"
   # 10.3 is the oldest supported version
diff --git a/homeassistant/const.py b/homeassistant/const.py
index 2daa6d91db2..1983932813e 100644
--- a/homeassistant/const.py
+++ b/homeassistant/const.py
@@ -24,7 +24,7 @@ if TYPE_CHECKING:
 
 APPLICATION_NAME: Final = "HomeAssistant"
 MAJOR_VERSION: Final = 2025
-MINOR_VERSION: Final = 8
+MINOR_VERSION: Final = 9
 PATCH_VERSION: Final = "0.dev0"
 __short_version__: Final = f"{MAJOR_VERSION}.{MINOR_VERSION}"
 __version__: Final = f"{__short_version__}.{PATCH_VERSION}"
diff --git a/pyproject.toml b/pyproject.toml
index 35a2bf2c7fb..71182e99560 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "homeassistant"
-version = "2025.8.0.dev0"
+version = "2025.9.0.dev0"
 license = "Apache-2.0"
 license-files = ["LICENSE*", "homeassistant/backports/LICENSE*"]
 description = "Open-source home automation platform running on Python 3."