diff --git a/.github/workflows/zulip-ci.yml b/.github/workflows/zulip-ci.yml
index 175d4a308..acbd57805 100644
--- a/.github/workflows/zulip-ci.yml
+++ b/.github/workflows/zulip-ci.yml
@@ -20,12 +20,6 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          # Bullseye ships with Python 3.9.2.
-          - docker_image: zulip/ci:bullseye
-            name: Debian 11 (Python 3.9, backend)
-            os: bullseye
-            legacy_client_interface: "4"
-            server_version: refs/tags/4.0
           # Ubuntu 22.04 ships with Python 3.10.6.
           - docker_image: zulip/ci:jammy
             name: Ubuntu 22.04 (Python 3.10, backend)
diff --git a/.github/workflows/zulip-tests.yml b/.github/workflows/zulip-tests.yml
index 5e3c46353..1855b01f2 100644
--- a/.github/workflows/zulip-tests.yml
+++ b/.github/workflows/zulip-tests.yml
@@ -16,10 +16,10 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
-      - name: Set up Python 3.9
+      - name: Set up Python 3.10
         uses: actions/setup-python@v6
         with:
-          python-version: "3.9"
+          python-version: "3.10"
 
       - name: Install dependencies
         run: tools/provision --force
@@ -35,7 +35,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest]
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11", "3.12"]
 
     steps:
       - uses: actions/checkout@v6
diff --git a/pyproject.toml b/pyproject.toml
index 28633465b..05fc4c027 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.black]
 line-length = 100
-target-version = ["py39"]
+target-version = ["py310"]
 
 [tool.isort]
 src_paths = [
diff --git a/zulip/README.md b/zulip/README.md
index 75845bfee..0759d1b55 100644
--- a/zulip/README.md
+++ b/zulip/README.md
@@ -3,7 +3,7 @@
 The [Zulip API](https://zulip.com/api) Python bindings require the
 following dependencies:
 
-* **Python (version >= 3.9)**
+* **Python (version >= 3.10)**
 * requests (version >= 0.12.1)
 
 **Note**: If you'd like to use the Zulip bindings with Python 2, we
diff --git a/zulip/setup.py b/zulip/setup.py
index 5092d84ed..62c90e5df 100755
--- a/zulip/setup.py
+++ b/zulip/setup.py
@@ -42,12 +42,11 @@ def recur_expand(target_root: Any, dir: Any) -> Generator[Tuple[str, List[str]],
         "Intended Audience :: Developers",
         "Topic :: Communications :: Chat",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",
     ],
-    python_requires=">=3.9",
+    python_requires=">=3.10",
     url="https://www.zulip.org/",
     project_urls={
         "Source": "https://github.com/zulip/python-zulip-api/",
diff --git a/zulip_bots/setup.py b/zulip_bots/setup.py
index dfa93c267..f13f26a8b 100644
--- a/zulip_bots/setup.py
+++ b/zulip_bots/setup.py
@@ -32,12 +32,11 @@
         "Intended Audience :: Developers",
         "Topic :: Communications :: Chat",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",
     ],
-    python_requires=">=3.9",
+    python_requires=">=3.10",
     url="https://www.zulip.org/",
     project_urls={
         "Source": "https://github.com/zulip/python-zulip-api/",
diff --git a/zulip_botserver/setup.py b/zulip_botserver/setup.py
index 4001dbd33..0a63c8691 100644
--- a/zulip_botserver/setup.py
+++ b/zulip_botserver/setup.py
@@ -20,12 +20,11 @@
         "Intended Audience :: Developers",
         "Topic :: Communications :: Chat",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",
     ],
-    python_requires=">=3.9",
+    python_requires=">=3.10",
     url="https://www.zulip.org/",
     project_urls={
         "Source": "https://github.com/zulip/python-zulip-api/",