diff --git a/.circleci/config.yml b/.circleci/config.yml
deleted file mode 100644
index d271bc8b4..000000000
--- a/.circleci/config.yml
+++ /dev/null
@@ -1,229 +0,0 @@
-# CircleCI configuration file
-#
-# Check https://circleci.com/docs/2.0/language-python/ for more details
-#
-version: 2.1
-
-orbs:
-  codecov: codecov/codecov@3.2.3
-
-references:
-  restore_keys: &restore_keys
-    keys:
-      - python-env-v1-{{ arch }}-{{ .Environment.CIRCLE_JOB }}-{{ checksum "setup.py" }}-{{ checksum "requirements/requirements-test.txt" }}-{{ checksum ".circleci/ci-oldest-reqs.txt" }}
-
-  save_key: &save_key
-    key: python-env-v1-{{ arch }}-{{ .Environment.CIRCLE_JOB }}-{{ checksum "setup.py" }}-{{ checksum "requirements/requirements-test.txt" }}-{{ checksum ".circleci/ci-oldest-reqs.txt" }}
-
-jobs:
-  linux-python-311: &test-template
-    docker:
-      - image: cimg/python:3.11
-
-    environment:
-      DEPENDENCIES: "NEWEST"
-      SIGNAC_VERSION: "signac"
-      PYTHON: python
-
-    working_directory: ~/repo
-
-    steps:
-      - checkout
-
-      - run:
-          name: Install dependencies
-          command: |
-            ${PYTHON} -m pip install --progress-bar off -U virtualenv --user
-            mkdir -p ./venv
-            ${PYTHON} -m virtualenv ./venv --clear
-            . venv/bin/activate
-            ${PYTHON} -m pip install --progress-bar off -U pip>=20.3
-            ${PYTHON} -m pip install --progress-bar off ${SIGNAC_VERSION}
-            # DEPENDENCIES can be "OLDEST" or "NEWEST"
-            if [ "${DEPENDENCIES}" == "OLDEST" ]; then
-              ${PYTHON} -m pip install --progress-bar off -r .circleci/ci-oldest-reqs.txt
-            else
-              ${PYTHON} -m pip install --progress-bar off -r requirements.txt
-              ${PYTHON} -m pip install --progress-bar off -r requirements/requirements-test.txt
-            fi
-
-      - run:
-          name: Run tests
-          command: |
-            . venv/bin/activate
-            ${PYTHON} -m pytest --cov=flow --cov-config=setup.cfg --cov-report=xml tests/ -v
-
-      - store_artifacts:
-          path: test-reports
-          destination: test-reports
-
-  linux-python-311-signac-latest:
-    <<: *test-template
-    environment:
-      DEPENDENCIES: "NEWEST"
-      SIGNAC_VERSION: "git+ssh://git@github.com/glotzerlab/signac.git"
-      PYTHON: python
-  linux-python-310:
-    <<: *test-template
-    docker:
-      - image: cimg/python:3.10
-  linux-python-39:
-    <<: *test-template
-    docker:
-      - image: cimg/python:3.9
-  linux-python-38:
-    <<: *test-template
-    docker:
-      - image: cimg/python:3.8
-  linux-python-38-oldest:
-    <<: *test-template
-    docker:
-      - image: cimg/python:3.8
-    environment:
-      DEPENDENCIES: "OLDEST"
-      SIGNAC_VERSION: "signac==1.8.0"
-      PYTHON: python
-
-  test-install-pip-python-311:
-    docker:
-      - image: cimg/python:3.11
-
-    environment:
-      PYTHON: python
-
-    steps:
-
-      - run:
-          name: install-with-pip
-          command: |
-            ${PYTHON} -m pip install --progress-bar off signac signac-flow
-
-      - run: &smoke-test
-          name: smoke-test
-          command: |
-            ${PYTHON} -m signac --version
-            ${PYTHON} -c 'import signac'
-            ${PYTHON} -m flow --version
-            ${PYTHON} -c 'import flow'
-
-  test-install-conda: &test-install-conda
-    environment:
-      # The default job does not specify the version, just like the
-      # instructions.
-      PYTHON_DEP: ""
-      PYTHON: python
-    docker:
-      - image: conda/miniconda3:latest
-
-    steps:
-
-      - run:
-          name: install-with-conda
-          command: |
-            conda install -c conda-forge signac signac-flow ${PYTHON_DEP} --yes
-
-      - run:
-          <<: *smoke-test
-
-  test-install-conda-python-311:
-    <<: *test-install-conda
-    environment:
-      PYTHON_DEP: "python=3.11"
-      PYTHON: python
-
-  check-metadata:
-    docker:
-      - image: cimg/python:3.11
-
-    working_directory: ~/repo
-
-    steps:
-      - checkout
-
-      - run:
-          name: install-dev-requirements
-          command: |
-            pip install --user -U -r requirements/requirements-test.txt
-
-      - run:
-          name: check-citation-metadata
-          command: |
-            ./.sync-zenodo-metadata.py --check > /dev/null
-
-  test-deploy-pypi:
-    docker:
-      - image: cimg/python:3.11
-    working_directory: ~/repo
-    steps:
-      - checkout
-      - run:
-          name: test-deploy-pypi
-          command: |
-            bash .circleci/deploy.bash testpypi
-
-  deploy-pypi:
-    docker:
-      - image: cimg/python:3.11
-    working_directory: ~/repo
-    steps:
-      - checkout
-      - run:
-          name: deploy-pypi
-          command: |
-            bash .circleci/deploy.bash pypi
-
-
-workflows:
-  version: 2
-  test:
-    jobs:
-      - linux-python-311:
-          post-steps:
-            - codecov/upload
-      - linux-python-310:
-          post-steps:
-            - codecov/upload
-      - linux-python-39:
-          post-steps:
-            - codecov/upload
-      - linux-python-38:
-          post-steps:
-            - codecov/upload
-      - linux-python-38-oldest:
-          post-steps:
-            - codecov/upload
-      - check-metadata:
-          filters:
-            branches:
-              only: /release\/.*/
-      - test-deploy-pypi:
-          filters:
-            branches:
-              only: /release\/.*/
-          requires:
-            - linux-python-311
-            - linux-python-310
-            - linux-python-39
-            - linux-python-38
-            - linux-python-38-oldest
-  nightly:
-    triggers:
-      - schedule:
-          cron: "0 0 * * *"
-          filters:
-            branches:
-              only:
-                - master
-    jobs:
-      - linux-python-311-signac-latest
-      - test-install-pip-python-311
-      - test-install-conda
-      - test-install-conda-python-311
-  deploy:
-    jobs:
-      - deploy-pypi:
-          filters:
-            branches:
-              ignore: /.*/
-            tags:
-              only: /v.*/
diff --git a/.circleci/deploy.bash b/.circleci/deploy.bash
deleted file mode 100755
index 20b0f94e3..000000000
--- a/.circleci/deploy.bash
+++ /dev/null
@@ -1,42 +0,0 @@
-#!/bin/bash
-
-set -e
-set -u
-
-python -m pip install --progress-bar off --user -U -r requirements/requirements-test.txt
-python -m pip install --progress-bar off --user -U twine wheel setuptools
-
-# PYPI_API_TOKEN - (Required, Secret) Token for the publisher's account on PyPI
-# TEST_PYPI_API_TOKEN - (Required, Secret) Token for the publisher's account on TestPyPI
-
-cat << EOF > ~/.pypirc
-[distutils]
-index-servers=
-    pypi
-    testpypi
-
-[pypi]
-username: __token__
-password: ${PYPI_API_TOKEN}
-
-[testpypi]
-repository: https://test.pypi.org/legacy/
-username: __token__
-password: ${TEST_PYPI_API_TOKEN}
-EOF
-
-# Create wheels and source distribution
-python setup.py bdist_wheel
-python setup.py sdist
-
-# Test generated wheel
-python -m pip install signac-flow --progress-bar off -U --force-reinstall -f dist/
-python -m pytest tests/ -v
-
-# Upload wheels
-if [[ "$1" == "testpypi" || "$1" == "pypi" ]]; then
-    python -m twine upload --skip-existing --repository $1 dist/*
-else
-    echo "A valid repository must be provided: pypi or testpypi."
-    exit 1
-fi
diff --git a/.circleci/ci-oldest-reqs.txt b/.github/workflows/ci-oldest-reqs.txt
similarity index 100%
rename from .circleci/ci-oldest-reqs.txt
rename to .github/workflows/ci-oldest-reqs.txt
diff --git a/.github/workflows/deploy-pypi.yml b/.github/workflows/deploy-pypi.yml
new file mode 100644
index 000000000..b1a4bdf11
--- /dev/null
+++ b/.github/workflows/deploy-pypi.yml
@@ -0,0 +1,18 @@
+name: Publish to PyPI
+
+on:
+  push:
+    tags:
+      - 'v*.*.*'
+
+concurrency:
+  group: "${{ github.workflow }}-${{ github.ref }}"
+  cancel-in-progress: true
+
+jobs:
+  build-and-test-sdist-and-wheels:
+    uses: ./.github/workflows/publish-packages.yml
+    with:
+      upload_to_test: false
+    secrets:
+      PYPI_API_TOKEN: ${{ secrets.PYPI_API_TOKEN }}
diff --git a/.github/workflows/deploy-test-pypi.yml b/.github/workflows/deploy-test-pypi.yml
new file mode 100644
index 000000000..d1fe98d94
--- /dev/null
+++ b/.github/workflows/deploy-test-pypi.yml
@@ -0,0 +1,18 @@
+name: Publish to TestPyPI
+
+on:
+  push:
+    branches:
+      - 'release/*.*.*'
+
+concurrency:
+  group: "${{ github.workflow }}-${{ github.ref }}"
+  cancel-in-progress: true
+
+jobs:
+  build-and-test-sdist-and-wheels:
+    uses: ./.github/workflows/publish-packages.yml
+    with:
+      upload_to_test: true
+    secrets:
+      TEST_PYPI_API_TOKEN: ${{ secrets.TEST_PYPI_API_TOKEN }}
diff --git a/.github/workflows/publish-packages.yml b/.github/workflows/publish-packages.yml
new file mode 100644
index 000000000..d07354a04
--- /dev/null
+++ b/.github/workflows/publish-packages.yml
@@ -0,0 +1,72 @@
+name: Publish packages
+
+on:
+  workflow_call:
+    inputs:
+      upload_to_test:
+        required: true
+        type: boolean
+    secrets:
+      TEST_PYPI_API_TOKEN:
+        required: false
+      PYPI_API_TOKEN:
+        required: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Check out repo
+      uses: actions/checkout@v3
+      with:
+        submodules: "recursive"
+    - name: Set up Python
+      uses: actions/setup-python@v4
+      with:
+        python-version: "3.11"
+    - name: Install dependencies
+      run: |
+        # We must explicitly install the requirements so that we can force
+        # installation of the local wheel below in case the version conflicts
+        # with published wheels (typically only possible during testing).
+        python -m pip install \
+        -r requirements.txt \
+        -r requirements-test.txt
+    - name: Install pypa/build
+      run:
+        python -m pip install build
+    - name: Build a binary wheel and a source tarball
+      run:
+        python -m build --sdist --wheel --outdir dist/ .
+    - name: Install wheel
+      run:
+        python -m pip install signac-flow --progress-bar off --no-index -f dist/
+    - name: Test with pytest
+      run:
+        python -m pytest -v tests/
+    - name: Upload artifact
+      uses: actions/upload-artifact@v2
+      with:
+          name: release
+          path: dist/
+
+  publish:
+    needs: [build]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download artifact
+        uses: actions/download-artifact@v2
+        with:
+            name: release
+            path: dist/
+      - name: Publish package to TestPyPI
+        if: ${{ inputs.upload_to_test }}
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          repository_url: https://test.pypi.org/legacy/
+          password: ${{ secrets.TEST_PYPI_API_TOKEN }}
+      - name: Publish package to PyPI
+        if: ${{ !inputs.upload_to_test }}
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          password: ${{ secrets.PYPI_API_TOKEN }}
diff --git a/.github/workflows/run-pytest.yml b/.github/workflows/run-pytest.yml
new file mode 100644
index 000000000..502b2feff
--- /dev/null
+++ b/.github/workflows/run-pytest.yml
@@ -0,0 +1,55 @@
+name: Run Unit Tests
+
+on:
+  # trigger on pull requests
+  pull_request:
+
+  # trigger on all commits to master
+  push:
+    branches:
+      - 'master'
+
+  # trigger on request
+  workflow_dispatch:
+concurrency:
+  group: "${{ github.workflow }}-${{ github.ref }}"
+  cancel-in-progress: true
+jobs:
+  test:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+        config: [ {python: '3.8', dependencies: 'newest'},
+                  {python: '3.9', dependencies: 'newest'},
+                  {python: '3.10', dependencies: 'newest'},
+                  {python: '3.11', dependencies: 'newest'},
+                  {python: '3.8', dependencies: 'oldest'} ]
+    steps:
+    - uses: actions/checkout@v3
+      with:
+        submodules: "recursive"
+    - name: Set up Python ${{ matrix.config.python }}
+      uses: actions/setup-python@v4
+      with:
+        python-version: ${{ matrix.config.python }}
+    - name: Install newest dependencies
+      run: |
+        pip install -r requirements/requirements-test.txt
+      if: ${{ matrix.config.dependencies == 'newest' }}
+    - name: Install oldest supported dependencies
+      # To prevent Dependabot from updating the pinnings in this "oldest"
+      # dependency list, we have to avoid the word "requirements" in the
+      # filename. That's why it is in the .github/ directory and named "reqs"
+      # instead of "requirements."
+      run: |
+        pip install -r .github/workflows/ci-oldest-reqs.txt
+      if: ${{ matrix.config.dependencies == 'oldest' }}
+    - name: Install the package
+      run: |
+        pip install -e .
+    - name: Test with pytest
+      run: |
+        pytest --cov=flow --cov-config=setup.cfg --cov-report=xml tests/ -v
+    - uses: codecov/codecov-action@v3
diff --git a/changelog.txt b/changelog.txt
index 0d636ea0d..8a94d2908 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -15,6 +15,7 @@ Changed
 +++++++
 
 - Placing ``@FlowProject.pre`` and ``@FlowProject.post`` before the ``FlowProject.operation`` decorator raises an error (#700).
+- Updated CI to use GitHub Actions (#698).
 
 Removed
 +++++++