diff --git a/.github/workflows/docker/shared.env b/.github/workflows/docker/shared.env
index 0c0344766..3b19cd3d5 100644
--- a/.github/workflows/docker/shared.env
+++ b/.github/workflows/docker/shared.env
@@ -1,5 +1,4 @@
 PYTHON_VERSIONS=(
-    cp39-cp39
     cp310-cp310
     cp311-cp311
     cp312-cp312
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index d09b2fb1c..2eb338e54 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -16,7 +16,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python: [ 3.9, 3.13 ]
+        python: [ "3.10", 3.13 ]
         os:  [ macos-latest, ubuntu-24.04, windows-latest ]
     defaults:
       run:
diff --git a/.github/workflows/wheels.yml b/.github/workflows/wheels.yml
index 43d351429..40d3ebbea 100644
--- a/.github/workflows/wheels.yml
+++ b/.github/workflows/wheels.yml
@@ -17,7 +17,7 @@ jobs:
     strategy:
       matrix:
         os: [macos-13, macos-14, macos-15]
-        python: [3.9, "3.10", 3.11, 3.12, 3.13]
+        python: ["3.10", 3.11, 3.12, 3.13]
     steps:
       - name: Checkout
         uses: actions/checkout@v4.2.2
@@ -70,7 +70,7 @@ jobs:
     runs-on: windows-latest
     strategy:
       matrix:
-        python: [3.9, "3.10", 3.11, 3.12, 3.13]
+        python: ["3.10", 3.11, 3.12, 3.13]
         arch: [x64]
     steps:
       - name: Checkout
@@ -123,10 +123,10 @@ jobs:
         uses: actions/checkout@v4.2.2
         with:
             submodules: true
-      - name: Set up Python 3.9
+      - name: Set up Python 3.10
         uses: actions/setup-python@v5.4.0
         with:
-          python-version: 3.9
+          python-version: "3.10"
       - name: Build sdist
         shell: bash
         run: |
@@ -155,7 +155,7 @@ jobs:
     strategy:
       matrix:
         os: [macos-13, macos-14, macos-15]
-        python: [3.9, "3.10", 3.11, 3.12, 3.13]
+        python: ["3.10", 3.11, 3.12, 3.13]
     steps:
       - name: Download wheels
         uses: actions/download-artifact@v4.2.0
@@ -181,7 +181,7 @@ jobs:
     needs: ['manylinux']
     strategy:
       matrix:
-        python: [3.9, "3.10", 3.11, 3.12, 3.13]
+        python: ["3.10", 3.11, 3.12, 3.13]
     steps:
       - name: Download wheels
         uses: actions/download-artifact@v4.2.0
@@ -209,7 +209,7 @@ jobs:
     needs: ['Windows']
     strategy:
       matrix:
-        python: [3.9, "3.10", 3.11, 3.12, 3.13]
+        python: ["3.10", 3.11, 3.12, 3.13]
     steps:
       - name: Download wheels
         uses: actions/download-artifact@v4.2.0
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 47c0e0ccb..6bfb4fd9f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,8 @@
 
 - Add support and wheels for Python3.13
 
+- Drop Python 3.9 support, require Python >= 3.10 ({pr}`2418`, {user}`benjeffery`)
+
 - Add wheels on Windows ({pr}`2414`, {issue}`2200`,{user}`benjeffery`)
 
 **Breaking changes**:
diff --git a/pyproject.toml b/pyproject.toml
index 83de6fc65..f03049f94 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,13 +5,12 @@ authors = [
 ]
 description = "Simulate genealogical trees and genomic sequence data using population genetic models"
 readme = "README.md"
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 license = {text = "GNU GPLv3+"}
 classifiers = [
     "Programming Language :: C",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",