diff --git a/libcxx/utils/ci/buildkite-pipeline-clang.yml b/libcxx/utils/ci/buildkite-pipeline-clang.yml
--- a/libcxx/utils/ci/buildkite-pipeline-clang.yml
+++ b/libcxx/utils/ci/buildkite-pipeline-clang.yml
@@ -23,8 +23,9 @@
       # We use Release here to avoid including debug information. Otherwise, the clang binary is very large, which
       # is problematic because we need to upload the artifacts for other jobs to use. This may seem like nothing,
       # but with the number of jobs we run daily, this can result in thousands of GB of network I/O.
-      - "cmake -S llvm -B build -G Ninja -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=install -DLLVM_ENABLE_PROJECTS=\"clang;compiler-rt\""
+      - "cmake -S llvm -B build -G Ninja -DCMAKE_CXX_COMPILER_LAUNCHER="ccache" -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=install -DLLVM_ENABLE_PROJECTS=\"clang;compiler-rt\""
       - "ninja -C build install-clang install-clang-resource-headers"
+      - "ccache -s"
       - "tar -cJvf install.tar.xz install/"
       - "buildkite-agent artifact upload --debug install.tar.xz"
     env:
diff --git a/libcxx/utils/ci/run-buildbot b/libcxx/utils/ci/run-buildbot
--- a/libcxx/utils/ci/run-buildbot
+++ b/libcxx/utils/ci/run-buildbot
@@ -340,6 +340,7 @@
           -S "${MONOREPO_ROOT}/llvm" \
           -B "${BUILD_DIR}" \
           -GNinja -DCMAKE_MAKE_PROGRAM="${NINJA}" \
+          -DCMAKE_CXX_COMPILER_LAUNCHER="ccache" \
           -DCMAKE_BUILD_TYPE=RelWithDebInfo \
           -DCMAKE_INSTALL_PREFIX="${INSTALL_DIR}" \
           -DLLVM_ENABLE_PROJECTS="clang" \