diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1a05d09..6b3746a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,6 +17,12 @@ jobs:
       - uses: actions/setup-dotnet@v4
         with:
           global-json-file: global.json
+      - name: Cache NuGet packages
+        uses: actions/cache@v4
+        with:
+          path: ~/.nuget/packages
+          key: nuget-${{ runner.os }}-${{ hashFiles('**/*.csproj', '**/Directory.Packages.props', 'global.json') }}
+          restore-keys: nuget-${{ runner.os }}-
       - run: dotnet restore
       - run: dotnet build -c Release --no-restore
       - run: dotnet test -c Release --no-build --logger trx --results-directory test-results
@@ -33,6 +39,12 @@ jobs:
       - uses: actions/setup-dotnet@v4
         with:
           global-json-file: global.json
+      - name: Cache NuGet packages
+        uses: actions/cache@v4
+        with:
+          path: ~/.nuget/packages
+          key: nuget-${{ runner.os }}-${{ hashFiles('**/*.csproj', '**/Directory.Packages.props', 'global.json') }}
+          restore-keys: nuget-${{ runner.os }}-
       - run: dotnet restore
       # Local dev's `make format_check` scopes to OWN_PROJECTS (the Makefile's own list) to
       # skip vgi-rpc-csharp's vendored third_party/ when the sibling checkout is present as a
@@ -52,6 +64,12 @@ jobs:
       - uses: actions/setup-dotnet@v4
         with:
           global-json-file: global.json
+      - name: Cache NuGet packages
+        uses: actions/cache@v4
+        with:
+          path: ~/.nuget/packages
+          key: nuget-${{ runner.os }}-${{ hashFiles('**/*.csproj', '**/Directory.Packages.props', 'global.json') }}
+          restore-keys: nuget-${{ runner.os }}-
       - run: dotnet build -c Release
 
       - name: Checkout pinned vgi test suite
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 23558ed..ea78e10 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -16,6 +16,12 @@ jobs:
       - uses: actions/setup-dotnet@v4
         with:
           global-json-file: global.json
+      - name: Cache NuGet packages
+        uses: actions/cache@v4
+        with:
+          path: ~/.nuget/packages
+          key: nuget-${{ runner.os }}-${{ hashFiles('**/*.csproj', '**/Directory.Packages.props', 'global.json') }}
+          restore-keys: nuget-${{ runner.os }}-
 
       - name: Verify tag matches Directory.Build.props version
         run: |