diff --git a/lldb/cmake/modules/LLDBStandalone.cmake b/lldb/cmake/modules/LLDBStandalone.cmake
--- a/lldb/cmake/modules/LLDBStandalone.cmake
+++ b/lldb/cmake/modules/LLDBStandalone.cmake
@@ -1,5 +1,12 @@
 option(LLVM_INSTALL_TOOLCHAIN_ONLY "Only include toolchain files in the 'install' target." OFF)
 
+if(NOT Clang_DIR)
+  # ClangConfig.cmake is usually found in the clang directory
+  # next to LLVM's module directory.
+  set(Clang_DIR ${LLVM_DIR}/../clang)
+  message(STATUS "Inferred Clang_DIR: ${Clang_DIR}")
+endif()
+
 find_package(LLVM REQUIRED CONFIG HINTS "${LLVM_DIR}" NO_CMAKE_FIND_ROOT_PATH)
 find_package(Clang REQUIRED CONFIG HINTS "${Clang_DIR}" NO_CMAKE_FIND_ROOT_PATH)
 
diff --git a/lldb/docs/resources/build.rst b/lldb/docs/resources/build.rst
--- a/lldb/docs/resources/build.rst
+++ b/lldb/docs/resources/build.rst
@@ -323,7 +323,6 @@
   > cmake -B /path/to/lldb-build \
           -C /path/to/llvm-project/lldb/cmake/caches/Apple-lldb-Xcode.cmake \
           -DLLVM_DIR=/path/to/llvm-build/lib/cmake/llvm \
-          -DClang_DIR=/path/to/llvm-build/lib/cmake/clang \
           llvm-project/lldb
   > open lldb.xcodeproj
   > cmake --build /path/to/lldb-build --target check-lldb