diff --git a/.github/workflows/ci-daily.yml b/.github/workflows/ci-daily.yml
index 35a3cf5e47c..48d63626403 100644
--- a/.github/workflows/ci-daily.yml
+++ b/.github/workflows/ci-daily.yml
@@ -14,7 +14,7 @@ jobs:
     name: Pytest Ubuntu
     strategy:
       matrix:
-        python-version: ['3.9', '3.10', '3.11']
+        python-version: ['3.10', '3.11']
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v4
@@ -44,7 +44,7 @@ jobs:
     name: Pytest Windows
     strategy:
       matrix:
-        python-version: ['3.9', '3.10', '3.11']
+        python-version: ['3.10', '3.11']
     runs-on: windows-2019
     steps:
       - uses: actions/checkout@v4
@@ -70,7 +70,7 @@ jobs:
     name: Pytest MacOS
     strategy:
       matrix:
-        python-version: ['3.9', '3.10', '3.11']
+        python-version: ['3.10', '3.11']
     runs-on: macos-latest
     steps:
       - uses: actions/checkout@v4
diff --git a/.github/workflows/ci-weekly.yml b/.github/workflows/ci-weekly.yml
index f7f525e51db..7ec25512eb6 100644
--- a/.github/workflows/ci-weekly.yml
+++ b/.github/workflows/ci-weekly.yml
@@ -23,7 +23,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install requirements
         run: pip install -r dev_tools/requirements/isolated-base.env.txt
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5b63193bbfa..9a1ecc74746 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -20,7 +20,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Misc
         run: check/misc
@@ -31,7 +31,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install dependencies
         run: pip install -r dev_tools/requirements/deps/packaging.txt
@@ -46,7 +46,7 @@ jobs:
           fetch-depth: 0
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install dependencies
         run: pip install -r dev_tools/requirements/deps/format.txt
@@ -59,7 +59,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install mypy
         run: pip install -r dev_tools/requirements/mypy.env.txt
@@ -74,7 +74,7 @@ jobs:
           fetch-depth: 0
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install changed files test dependencies
         run: dev_tools/conf/pip-install-minimal-for-pytest-changed-files.sh
@@ -87,7 +87,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install pylint
         run: pip install -r dev_tools/requirements/pylint.env.txt
@@ -102,7 +102,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install requirements
         run: pip install -r dev_tools/requirements/dev.env.txt
@@ -117,7 +117,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install requirements
         run: pip install -r dev_tools/requirements/deps/tensorflow-docs.txt
@@ -139,7 +139,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install dependencies
         run: pip install -r dev_tools/requirements/isolated-base.env.txt
@@ -149,7 +149,7 @@ jobs:
     name: Pytest Ubuntu
     strategy:
       matrix:
-        python-version: [ '3.9', '3.10', '3.11' ]
+        python-version: [ '3.10', '3.11' ]
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v4
@@ -178,7 +178,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install requirements
         run: pip install pip-tools
@@ -194,7 +194,7 @@ jobs:
           fetch-depth: 0
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install requirements
         run: |
@@ -210,7 +210,7 @@ jobs:
           fetch-depth: 0
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - uses: actions/cache@v4
         with:
@@ -234,7 +234,7 @@ jobs:
     name: Pytest Windows
     strategy:
       matrix:
-        python-version: [ '3.9', '3.10', '3.11' ]
+        python-version: [ '3.10', '3.11' ]
     runs-on: windows-2019
     steps:
       - uses: actions/checkout@v4
@@ -259,7 +259,7 @@ jobs:
     name: Pytest MacOS
     strategy:
       matrix:
-        python-version: [ '3.9', '3.10', '3.11' ]
+        python-version: [ '3.10', '3.11' ]
     runs-on: macos-latest
     steps:
       - uses: actions/checkout@v4
@@ -292,7 +292,7 @@ jobs:
           fetch-depth: 0
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install requirements
         run: pip install -r dev_tools/requirements/isolated-base.env.txt
@@ -310,7 +310,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install requirements
         run: pip install -r dev_tools/requirements/notebooks.env.txt
diff --git a/.github/workflows/release-main.yml b/.github/workflows/release-main.yml
index 607583b95f3..b5301c97dbd 100644
--- a/.github/workflows/release-main.yml
+++ b/.github/workflows/release-main.yml
@@ -15,7 +15,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
           architecture: 'x64'
       - name: Install dependencies
         run: |
diff --git a/Dockerfile b/Dockerfile
index 142c212995c..64520f6d335 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.9-slim AS cirq_base
+FROM python:3.10-slim AS cirq_base
 
 # Install dependencies.
 # rm -rf /var/lib/apt/lists/* cleans up apt cache. See https://docs.docker.com/develop/develop-images/dockerfile_best-practices/
diff --git a/asv.conf.json b/asv.conf.json
index 18449918fee..07f27ab48a0 100644
--- a/asv.conf.json
+++ b/asv.conf.json
@@ -8,7 +8,7 @@
     "dvcs": "git",
     "environment_type": "virtualenv",
     "show_commit_url": "https://github.com/quantumlib/Cirq/commit/",
-    "pythons": ["3.9"],
+    "pythons": ["3.10"],
     "matrix": {"env_nobuild": {"PYTHONOPTIMIZE": ["-O", ""]}},
     "benchmark_dir": "benchmarks",
     "env_dir": ".asv/env",
diff --git a/benchmarks/README.md b/benchmarks/README.md
index 37286d8e295..0e9ef527d5f 100644
--- a/benchmarks/README.md
+++ b/benchmarks/README.md
@@ -13,7 +13,7 @@ To run all benchmarks, navigate to the root Cirq directory at the command line a
 
 You can also pass arguments to the script, which would be forwarded to the `asv run` command. For eg:
 ```bash
-./check/asv_run --quick --bench bench_examples --python 3.9
+./check/asv_run --quick --bench bench_examples --python 3.10
 ```
 
 Please refer [Running Benchmarks guide by ASV](https://asv.readthedocs.io/en/stable/using.html#running-benchmarks) for more information. 
diff --git a/cirq-core/cirq/experiments/t1_decay_experiment.py b/cirq-core/cirq/experiments/t1_decay_experiment.py
index 0d44db7b412..a8ee85e70b5 100644
--- a/cirq-core/cirq/experiments/t1_decay_experiment.py
+++ b/cirq-core/cirq/experiments/t1_decay_experiment.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Any, Optional, TYPE_CHECKING
+from typing import Any, Optional, Sequence, TYPE_CHECKING, cast
 
 import warnings
 import pandas as pd
@@ -77,7 +77,12 @@ def t1_decay(
 
     var = sympy.Symbol('delay_ns')
 
-    sweep = study.Linspace(var, start=min_delay_nanos, stop=max_delay_nanos, length=num_points)
+    if min_delay_nanos == 0:
+        min_delay_nanos = 0.4
+    sweep_vals_ns = np.unique(
+        np.round(np.logspace(np.log10(min_delay_nanos), np.log10(max_delay_nanos), num_points))
+    )
+    sweep = study.Points(var, cast(Sequence[float], sweep_vals_ns))
 
     circuit = circuits.Circuit(
         ops.X(qubit), ops.wait(qubit, nanos=var), ops.measure(qubit, key='output')
@@ -118,8 +123,8 @@ def data(self) -> pd.DataFrame:
     def constant(self) -> float:
         """The t1 decay constant."""
 
-        def exp_decay(x, t1):
-            return np.exp(-x / t1)
+        def exp_decay(x, t1, a, b):
+            return a * np.exp(-x / t1) + b
 
         xs = self._data['delay_ns']
         ts = self._data['true_count']
@@ -132,8 +137,8 @@ def exp_decay(x, t1):
 
         # Fit to exponential decay to find the t1 constant
         try:
-            popt, _ = optimize.curve_fit(exp_decay, xs, probs, p0=[t1_guess])
-            t1 = popt[0]
+            self.popt, _ = optimize.curve_fit(exp_decay, xs, probs, p0=[t1_guess, 1.0, 0.0])
+            t1 = self.popt[0]
             return t1
         except RuntimeError:
             warnings.warn("Optimal parameters could not be found for curve fit", RuntimeWarning)
@@ -166,7 +171,9 @@ def plot(
         ax.plot(xs, ts / (fs + ts), 'ro-', **plot_kwargs)
 
         if include_fit and not np.isnan(self.constant):
-            ax.plot(xs, np.exp(-xs / self.constant), label='curve fit')
+            t1 = self.constant
+            t1, a, b = self.popt
+            ax.plot(xs, a * np.exp(-xs / t1) + b, label='curve fit')
             plt.legend()
 
         ax.set_xlabel(r"Delay between initialization and measurement (nanoseconds)")
diff --git a/cirq-core/cirq/experiments/t1_decay_experiment_test.py b/cirq-core/cirq/experiments/t1_decay_experiment_test.py
index 64d220dd5c1..acbd7526433 100644
--- a/cirq-core/cirq/experiments/t1_decay_experiment_test.py
+++ b/cirq-core/cirq/experiments/t1_decay_experiment_test.py
@@ -53,7 +53,7 @@ def noisy_moment(self, moment, system_qubits):
         repetitions=10,
         max_delay=cirq.Duration(nanos=500),
     )
-    results.plot()
+    results.plot(include_fit=True)
 
 
 def test_result_eq():
@@ -61,7 +61,7 @@ def test_result_eq():
     eq.make_equality_group(
         lambda: cirq.experiments.T1DecayResult(
             data=pd.DataFrame(
-                columns=['delay_ns', 'false_count', 'true_count'], index=[0], data=[[100.0, 2, 8]]
+                columns=['delay_ns', 'false_count', 'true_count'], index=[0], data=[[100, 2, 8]]
             )
         )
     )
@@ -103,7 +103,7 @@ def noisy_moment(self, moment, system_qubits):
         data=pd.DataFrame(
             columns=['delay_ns', 'false_count', 'true_count'],
             index=range(4),
-            data=[[100.0, 0, 10], [400.0, 0, 10], [700.0, 10, 0], [1000.0, 10, 0]],
+            data=[[100.0, 0, 10], [215.0, 0, 10], [464.0, 0, 10], [1000.0, 10, 0]],
         )
     )
 
@@ -117,13 +117,14 @@ def test_all_on_results():
         min_delay=cirq.Duration(nanos=100),
         max_delay=cirq.Duration(micros=1),
     )
-    assert results == cirq.experiments.T1DecayResult(
+    desired = cirq.experiments.T1DecayResult(
         data=pd.DataFrame(
             columns=['delay_ns', 'false_count', 'true_count'],
             index=range(4),
-            data=[[100.0, 0, 10], [400.0, 0, 10], [700.0, 0, 10], [1000.0, 0, 10]],
+            data=[[100.0, 0, 10], [215.0, 0, 10], [464.0, 0, 10], [1000.0, 0, 10]],
         )
     )
+    assert results == desired, f'{results.data=} {desired.data=}'
 
 
 def test_all_off_results():
@@ -135,13 +136,14 @@ def test_all_off_results():
         min_delay=cirq.Duration(nanos=100),
         max_delay=cirq.Duration(micros=1),
     )
-    assert results == cirq.experiments.T1DecayResult(
+    desired = cirq.experiments.T1DecayResult(
         data=pd.DataFrame(
             columns=['delay_ns', 'false_count', 'true_count'],
             index=range(4),
-            data=[[100.0, 10, 0], [400.0, 10, 0], [700.0, 10, 0], [1000.0, 10, 0]],
+            data=[[100.0, 10, 0], [215.0, 10, 0], [464.0, 10, 0], [1000.0, 10, 0]],
         )
     )
+    assert results == desired, f'{results.data=} {desired.data=}'
 
 
 @pytest.mark.usefixtures('closefigures')
@@ -150,28 +152,14 @@ def test_curve_fit_plot_works():
         data=pd.DataFrame(
             columns=['delay_ns', 'false_count', 'true_count'],
             index=range(4),
-            data=[[100.0, 6, 4], [400.0, 10, 0], [700.0, 10, 0], [1000.0, 10, 0]],
+            data=[[100.0, 6, 4], [215.0, 10, 0], [464.0, 10, 0], [1000.0, 10, 0]],
         )
     )
 
     good_fit.plot(include_fit=True)
 
 
-@pytest.mark.usefixtures('closefigures')
-def test_curve_fit_plot_warning():
-    bad_fit = cirq.experiments.T1DecayResult(
-        data=pd.DataFrame(
-            columns=['delay_ns', 'false_count', 'true_count'],
-            index=range(4),
-            data=[[100.0, 10, 0], [400.0, 10, 0], [700.0, 10, 0], [1000.0, 10, 0]],
-        )
-    )
-
-    with pytest.warns(RuntimeWarning, match='Optimal parameters could not be found for curve fit'):
-        bad_fit.plot(include_fit=True)
-
-
-@pytest.mark.parametrize('t1', [200, 500, 700])
+@pytest.mark.parametrize('t1', [200.0, 500.0, 700.0])
 def test_noise_model_continous(t1):
     class GradualDecay(cirq.NoiseModel):
         def __init__(self, t1: float):
@@ -196,10 +184,10 @@ def noisy_moment(self, moment, system_qubits):
     results = cirq.experiments.t1_decay(
         sampler=cirq.DensityMatrixSimulator(noise=GradualDecay(t1)),
         qubit=cirq.GridQubit(0, 0),
-        num_points=4,
+        num_points=10,
         repetitions=10,
-        min_delay=cirq.Duration(nanos=100),
-        max_delay=cirq.Duration(micros=1),
+        min_delay=cirq.Duration(nanos=1),
+        max_delay=cirq.Duration(micros=10),
     )
 
     assert np.isclose(results.constant, t1, 50)
diff --git a/dev_tools/packaging/packaging_test.sh b/dev_tools/packaging/packaging_test.sh
index 30d1a51f553..320e2e8ed01 100755
--- a/dev_tools/packaging/packaging_test.sh
+++ b/dev_tools/packaging/packaging_test.sh
@@ -28,7 +28,7 @@ trap '{ rm -rf "${tmp_dir}"; }' EXIT
 
 # New virtual environment
 echo "Working in a fresh virtualenv at ${tmp_dir}/env"
-python3.9 -m venv "${tmp_dir}/env"
+python3.10 -m venv "${tmp_dir}/env"
 
 export CIRQ_PRE_RELEASE_VERSION
 CIRQ_PRE_RELEASE_VERSION=$(dev_tools/packaging/generate-dev-version-id.sh)
diff --git a/dev_tools/pr_monitor/Dockerfile b/dev_tools/pr_monitor/Dockerfile
index 04f7c57263e..10769b7c9a5 100644
--- a/dev_tools/pr_monitor/Dockerfile
+++ b/dev_tools/pr_monitor/Dockerfile
@@ -23,7 +23,7 @@
 # value of the cirqbot-api-key secret.
 ########################################################################################
 
-FROM python:3.9-slim
+FROM python:3.10-slim
 
 RUN mkdir -p /app/dev_tools/pr_monitor
 WORKDIR /app
diff --git a/docs/dev/development.md b/docs/dev/development.md
index 146e66df471..740db5efdd2 100644
--- a/docs/dev/development.md
+++ b/docs/dev/development.md
@@ -94,7 +94,7 @@ See the previous section for instructions.
 
 1. Install system dependencies.
 
-    Make sure you have python 3.9 or greater.
+    Make sure you have python 3.10 or greater.
     You can install most other dependencies via `apt-get`:
 
     ```bash
diff --git a/docs/noise/qcvv/parallel_xeb.ipynb b/docs/noise/qcvv/parallel_xeb.ipynb
index 920f14b0b52..57ef5b0d34b 100644
--- a/docs/noise/qcvv/parallel_xeb.ipynb
+++ b/docs/noise/qcvv/parallel_xeb.ipynb
@@ -65,7 +65,7 @@
     "    import cirq\n",
     "except ImportError:\n",
     "    print(\"installing cirq...\")\n",
-    "    !pip install --quiet cirq\n",
+    "    !pip install --quiet cirq --pre\n",
     "    print(\"installed cirq.\")"
    ]
   },
@@ -88,7 +88,63 @@
    "outputs": [],
    "source": [
     "import cirq\n",
-    "import numpy as np"
+    "import numpy as np\n",
+    "\n",
+    "%matplotlib inline\n",
+    "from matplotlib import pyplot as plt"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Parallel XEB with library functions\n",
+    "The entire XEB workflow can be run by calling `cirq.experiments.parallel_two_qubit_xeb` and the combined single-qubit randomized benchmarking (RB) and XEB workflows can be run by calling `cirq.experiments.run_rb_and_xeb`."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Simulation\n",
+    "qubits = cirq.GridQubit.rect(3, 2, 4, 3)\n",
+    "result = cirq.experiments.parallel_two_qubit_xeb(\n",
+    "    sampler=cirq.DensityMatrixSimulator(noise=cirq.depolarize(5e-3)),  # Any simulator or a ProcessorSampler.\n",
+    "    qubits=qubits \n",
+    ")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# The returned result is an instance of the `TwoQubitXEBResult` class which provides visualization methods like \n",
+    "result.plot_heatmap();  # plot the heatmap of XEB errors\n",
+    "result.plot_fitted_exponential(*qubits[:2]);  # plot the fitted model of xeb error of a qubit pair.\n",
+    "result.plot_histogram();  # plot a histogram of all xeb errors."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# `TwoQubitXEBResult` also has methods to retrieve errors.\n",
+    "print('pauli errors:', result.pauli_error())\n",
+    "print('xeb errors:', result.xeb_error(*qubits[:2]))\n",
+    "print('xeb fidelity:', result.xeb_fidelity(*qubits[:2]))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The `run_rb_and_xeb` method returns an object of type [InferredXEBResult](https://github.com/quantumlib/Cirq/blob/bc766606b94744f80da435c522d16a34529ae671/cirq-core/cirq/experiments/two_qubit_xeb.py#L188C7-L188C24) which is like [TwoQubitXEBResult](https://github.com/quantumlib/Cirq/blob/bc766606b94744f80da435c522d16a34529ae671/cirq-core/cirq/experiments/two_qubit_xeb.py#L56) except that it removes the single-qubit errors obtained from the single-qubit randomized benchmarking (RB) experiment to isolate the error from the two qubit gate."
    ]
   },
   {
@@ -97,6 +153,9 @@
     "id": "ace31cc4d258"
    },
    "source": [
+    "# Step by step XEB\n",
+    "The rest of this notebook explains how the `parallel_two_qubit_xeb` works internally. Note that the notebook uses `SQRT_ISWAP` as the entangling gate while `parallel_two_qubit_xeb` and `run_rb_and_xeb` default to `CZ`.\n",
+    "\n",
     "## Set up Random Circuits\n",
     "\n",
     "We create a library of 10 random, two-qubit `circuits` using the sqrt(ISWAP) gate. These library circuits will be mixed-and-matched among all the pairs on the device we aim to characterize."
@@ -224,9 +283,6 @@
    },
    "outputs": [],
    "source": [
-    "%matplotlib inline\n",
-    "from matplotlib import pyplot as plt\n",
-    "\n",
     "fig, axes = plt.subplots(2,2, figsize=(9,6))\n",
     "for comb_layer, ax in zip(combs_by_layer, axes.reshape(-1)):\n",
     "    active_qubits = np.array(comb_layer.pairs).reshape(-1)\n",
@@ -500,6 +556,18 @@
   "kernelspec": {
    "display_name": "Python 3",
    "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.10.13"
   }
  },
  "nbformat": 4,
diff --git a/docs/start/install.md b/docs/start/install.md
index 156346f36ac..dc25e5e289c 100644
--- a/docs/start/install.md
+++ b/docs/start/install.md
@@ -12,7 +12,7 @@ If you want to create a development environment, see the [development page](../d
 
 ## Python version support
 
-Cirq currently supports python 3.9 and later.
+Cirq currently supports python 3.10 and later.
 We follow numpy's schedule for python version support defined in [NEP 29](https://numpy.org/neps/nep-0029-deprecation_policy.html),
 though we may deviate from that schedule by extending support for older python
 versions if they are needed by [Colab](https://colab.research.google.com/)
@@ -20,7 +20,7 @@ or internal Google systems.
 
 ## Installing on Linux
 
-0. Make sure you have python 3.9.0 or greater.
+0. Make sure you have python 3.10.0 or greater.
 
     See [Installing Python 3 on Linux](https://docs.python-guide.org/starting/install3/linux/) @ the hitchhiker's guide to python.
 
@@ -87,7 +87,7 @@ or internal Google systems.
 
 ## Installing on Mac OS X
 
-0. Make sure you have python 3.9.0 or greater.
+0. Make sure you have python 3.10.0 or greater.
 
     See [Installing Python 3 on Mac OS X](https://docs.python-guide.org/starting/install3/osx/) @ the hitchhiker's guide to python.
 
@@ -154,7 +154,7 @@ or internal Google systems.
 
 0. If you are using the [Windows Subsystem for Linux](https://docs.microsoft.com/en-us/windows/wsl/about), use the [Linux install instructions](#installing-on-linux) instead of these instructions.
 
-1. Make sure you have python 3.9.0 or greater.
+1. Make sure you have python 3.10.0 or greater.
 
     See [Installing Python 3 on Windows](https://docs.python-guide.org/starting/install3/win/) @ the hitchhiker's guide to python.
 
diff --git a/release.md b/release.md
index 1b98b1973a2..016577c40bd 100644
--- a/release.md
+++ b/release.md
@@ -82,7 +82,7 @@ release.
 
 ### Preparation
 
-System requirements: Linux, python3.9
+System requirements: Linux, python3.10
 
 For MINOR / MAJOR release: Make sure you're on an up-to-date main branch and 
 in cirq's root directory.