diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 027a72b..b833a11 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -28,7 +28,6 @@ jobs:
       matrix:
         os: [ubuntu-latest]
         environment-file:
-          - ci/39-oldest.yaml
           - ci/310-oldest.yaml
           - ci/310-latest.yaml
           - ci/311-latest.yaml
diff --git a/ci/39-oldest.yaml b/ci/39-oldest.yaml
deleted file mode 100644
index af3535e..0000000
--- a/ci/39-oldest.yaml
+++ /dev/null
@@ -1,19 +0,0 @@
-name: test
-channels:
-  - conda-forge
-dependencies:
-  - python=3.9
-  # required
-  - esda=2.4
-  - libpysal=4.8
-  - mapclassify=2.5
-  - quantecon=0.7
-  - scipy=1.8
-  - splot
-  # testing
-  - codecov
-  - ipywidgets
-  - matplotlib
-  - pytest
-  - pytest-cov
-  - pytest-xdist
diff --git a/docs/installation.rst b/docs/installation.rst
index 292e47a..78d334f 100644
--- a/docs/installation.rst
+++ b/docs/installation.rst
@@ -3,7 +3,7 @@
 Installation
 ============
 
-giddy currently supports python `3.9`_, `3.10`_, `3.11`_, and `3.12`_.
+giddy currently supports python `3.10`_, `3.11`_, and `3.12`_.
 Please make sure that you are operating in a python 3 environment.
 
 Installing released version
@@ -41,7 +41,6 @@ your fork. By making changes
 to your local clone and submitting a pull request to `pysal/giddy`_, you can
 contribute to the giddy development.
 
-.. _3.9: https://docs.python.org/3.9/
 .. _3.10: https://docs.python.org/3.10/
 .. _3.11: https://docs.python.org/3.11/
 .. _3.12: https://docs.python.org/3.12/
diff --git a/pyproject.toml b/pyproject.toml
index 74c1a07..9a31ffb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -21,7 +21,7 @@ classifiers = [
     "Intended Audience :: Science/Research",
     "Topic :: Scientific/Engineering :: GIS",
 ]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = [
     "esda>=2.4",
     "libpysal>=4.8",