diff --git a/changelog.d/17887.misc b/changelog.d/17887.misc
new file mode 100644
index 0000000000..6be32caee6
--- /dev/null
+++ b/changelog.d/17887.misc
@@ -0,0 +1 @@
+Bump the default Python version in the Synapse Dockerfile from 3.11 -> 3.12.
\ No newline at end of file
diff --git a/docker/Dockerfile b/docker/Dockerfile
index 1da196b12e..a4931011a7 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -20,7 +20,7 @@
 # `poetry export | pip install -r /dev/stdin`, but beware: we have experienced bugs in
 # in `poetry export` in the past.
 
-ARG PYTHON_VERSION=3.11
+ARG PYTHON_VERSION=3.12
 
 ###
 ### Stage 0: generate requirements.txt