diff --git a/.ci/scripts/calculate_jobs.py b/.ci/scripts/calculate_jobs.py
index 1ddea715b0..67b747195a 100755
--- a/.ci/scripts/calculate_jobs.py
+++ b/.ci/scripts/calculate_jobs.py
@@ -81,6 +81,14 @@ trial_postgres_tests = [
         "postgres-version": "17",
         "extras": "all",
     },
+    # Postgres through the native Rust driver rather than psycopg2.
+    {
+        "python-version": "3.14",
+        "database": "postgres",
+        "postgres-version": "17",
+        "extras": "all",
+        "driver": "rust",
+    },
 ]
 
 # Ensure that Synapse passes unit tests even with no extra dependencies installed.
diff --git a/.github/workflows/complement_tests.yml b/.github/workflows/complement_tests.yml
index cb43c1a106..f6b14a12b9 100644
--- a/.github/workflows/complement_tests.yml
+++ b/.github/workflows/complement_tests.yml
@@ -37,6 +37,10 @@ jobs:
           - arrangement: workers
             database: Postgres
 
+          - arrangement: monolith
+            database: Postgres
+            driver: rust
+
     steps:
       - name: Checkout synapse codebase
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
@@ -114,6 +118,7 @@ jobs:
         env:
           POSTGRES: ${{ (matrix.database == 'Postgres') && 1 || '' }}
           WORKERS: ${{ (matrix.arrangement == 'workers') && 1 || '' }}
+          RUST_DRIVER: ${{ (matrix.driver == 'rust') && 1 || '' }}
 
       - name: Formatted sanity check Complement test logs
         # Always run this step if we attempted to run the Complement tests.
@@ -146,6 +151,7 @@ jobs:
         env:
           POSTGRES: ${{ (matrix.database == 'Postgres') && 1 || '' }}
           WORKERS: ${{ (matrix.arrangement == 'workers') && 1 || '' }}
+          RUST_DRIVER: ${{ (matrix.driver == 'rust') && 1 || '' }}
           TEST_ONLY_IGNORE_POETRY_LOCKFILE: ${{ inputs.use_latest_deps && 1 || '' }}
           TEST_ONLY_SKIP_DEP_HASH_VERIFICATION: ${{ inputs.use_twisted_trunk  && 1 || '' }}
 
@@ -183,6 +189,7 @@ jobs:
         env:
           POSTGRES: ${{ (matrix.database == 'Postgres') && 1 || '' }}
           WORKERS: ${{ (matrix.arrangement == 'workers') && 1 || '' }}
+          RUST_DRIVER: ${{ (matrix.driver == 'rust') && 1 || '' }}
           TEST_ONLY_IGNORE_POETRY_LOCKFILE: ${{ inputs.use_latest_deps && 1 || '' }}
           TEST_ONLY_SKIP_DEP_HASH_VERIFICATION: ${{ inputs.use_twisted_trunk  && 1 || '' }}
 
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 14a4fcdc4e..a4daef4fbd 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -449,6 +449,7 @@ jobs:
           SYNAPSE_POSTGRES_HOST: /var/run/postgresql
           SYNAPSE_POSTGRES_USER: postgres
           SYNAPSE_POSTGRES_PASSWORD: postgres
+          SYNAPSE_TEST_RUST_DRIVER: ${{ matrix.job.driver == 'rust' || '' }}
       - name: Dump logs
         # Logs are most useful when the command fails, always include them.
         if: ${{ always() }}
@@ -725,6 +726,21 @@ jobs:
       - linting-done
       - changes
 
+    # The native Postgres driver's tests run against a live server and are
+    # skipped without one.
+    services:
+      postgres:
+        image: postgres:17
+        env:
+          POSTGRES_PASSWORD: postgres
+        ports:
+          - 5432:5432
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
@@ -735,6 +751,8 @@ jobs:
       - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2.9.2
 
       - run: cargo test
+        env:
+          SYNAPSE_TEST_POSTGRES_DSN: host=localhost user=postgres password=postgres dbname=postgres
 
   # We want to ensure that the cargo benchmarks still compile, which requires a
   # nightly compiler.
diff --git a/docker/complement/conf/start_for_complement.sh b/docker/complement/conf/start_for_complement.sh
index e0d30abed3..e0cd275ff3 100755
--- a/docker/complement/conf/start_for_complement.sh
+++ b/docker/complement/conf/start_for_complement.sh
@@ -6,7 +6,7 @@ set -e
 
 echo "Complement Synapse launcher"
 echo "  Args: $*"
-echo "  Env: SYNAPSE_COMPLEMENT_DATABASE=$SYNAPSE_COMPLEMENT_DATABASE SYNAPSE_COMPLEMENT_USE_WORKERS=$SYNAPSE_COMPLEMENT_USE_WORKERS SYNAPSE_COMPLEMENT_USE_ASYNCIO_REACTOR=$SYNAPSE_COMPLEMENT_USE_ASYNCIO_REACTOR"
+echo "  Env: SYNAPSE_COMPLEMENT_DATABASE=$SYNAPSE_COMPLEMENT_DATABASE SYNAPSE_COMPLEMENT_USE_WORKERS=$SYNAPSE_COMPLEMENT_USE_WORKERS SYNAPSE_COMPLEMENT_USE_ASYNCIO_REACTOR=$SYNAPSE_COMPLEMENT_USE_ASYNCIO_REACTOR SYNAPSE_USE_RUST_DRIVER=$SYNAPSE_USE_RUST_DRIVER"
 
 function log {
     d=$(printf '%(%Y-%m-%d %H:%M:%S)T,%.3s\n' ${EPOCHREALTIME/./ })
diff --git a/scripts-dev/complement.sh b/scripts-dev/complement.sh
index d8e553f446..ccbbc7b924 100755
--- a/scripts-dev/complement.sh
+++ b/scripts-dev/complement.sh
@@ -358,6 +358,12 @@ main() {
     export PASS_SYNAPSE_COMPLEMENT_USE_ASYNCIO_REACTOR=true
   fi
 
+  if [[ -n "$RUST_DRIVER" ]]; then
+    # Talk to Postgres through the native Rust driver (`use_rust_driver`)
+    # instead of psycopg2. Only meaningful with POSTGRES=1.
+    export PASS_SYNAPSE_USE_RUST_DRIVER=true
+  fi
+
   if [[ -n "$UNIX_SOCKETS" ]]; then
     # Enable full on Unix socket mode for Synapse, Redis and Postgresql
     export PASS_SYNAPSE_USE_UNIX_SOCKET=1