diff --git a/README.md b/README.md
index d5199a1fa..f2745e611 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,7 @@ Note that you can
 
  * cmake >= 2.8.5
  * gcc >= 5.0.0 or clang >= 3.6.0
- * LLVM, Clang, LLD development libraries == 9.x, compiled with the same gcc or clang version above
+ * LLVM, Clang, LLD development libraries == 10.x, compiled with the same gcc or clang version above
    - Use the system package manager, or [build from source](https://github.com/ziglang/zig/wiki/How-to-build-LLVM,-libclang,-and-liblld-from-source#posix).
 
 ##### Windows
@@ -37,7 +37,7 @@ Note that you can
    - 2015 (version 14)
    - 2017 (version 15.8)
    - 2019 (version 16)
- * LLVM, Clang, LLD development libraries == 9.x
+ * LLVM, Clang, LLD development libraries == 10.x
    - Use the [pre-built binaries](https://github.com/ziglang/zig/wiki/Building-Zig-on-Windows) or [build from source](https://github.com/ziglang/zig/wiki/How-to-build-LLVM,-libclang,-and-liblld-from-source#windows).
 
 #### Instructions
@@ -54,8 +54,8 @@ make install
 ##### MacOS
 
 ```
-brew install cmake llvm@9
-brew outdated llvm@9 || brew upgrade llvm@9
+brew install cmake llvm@10
+brew outdated llvm@10 || brew upgrade llvm@10
 mkdir build
 cd build
 cmake .. -DCMAKE_PREFIX_PATH=$(brew --prefix llvm)
diff --git a/ci/azure/macos_script b/ci/azure/macos_script
index 74500ddf9..790b276f0 100755
--- a/ci/azure/macos_script
+++ b/ci/azure/macos_script
@@ -8,7 +8,7 @@ system_profiler SPHardwareDataType
 brew install s3cmd gcc@8
 
 ZIGDIR="$(pwd)"
-CACHE_BASENAME="llvm+clang-9.0.0-macos-x86_64-gcc8-release"
+CACHE_BASENAME="llvm+clang-10.0.0-macos-x86_64-gcc8-release"
 PREFIX="$HOME/$CACHE_BASENAME"
 TMPDIR="$HOME/tmpz"
 JOBS="-j2"
@@ -44,18 +44,18 @@ else
   rm $PREFIX/lib/libz*dylib
 
   cd $TMPDIR
-  wget https://releases.llvm.org/9.0.0/llvm-9.0.0.src.tar.xz
-  tar xf llvm-9.0.0.src.tar.xz
-  cd llvm-9.0.0.src/
+  wget https://releases.llvm.org/10.0.0/llvm-10.0.0.src.tar.xz
+  tar xf llvm-10.0.0.src.tar.xz
+  cd llvm-10.0.0.src/
   mkdir build
   cd build
   cmake .. -DCMAKE_INSTALL_PREFIX=$PREFIX -DCMAKE_PREFIX_PATH=$PREFIX -DCMAKE_BUILD_TYPE=Release -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD="AVR" -DLLVM_ENABLE_LIBXML2=OFF -DLLVM_ENABLE_TERMINFO=OFF
   make $JOBS install
 
   cd $TMPDIR
-  wget https://releases.llvm.org/9.0.0/cfe-9.0.0.src.tar.xz
-  tar xf cfe-9.0.0.src.tar.xz
-  cd cfe-9.0.0.src/
+  wget https://releases.llvm.org/10.0.0/cfe-10.0.0.src.tar.xz
+  tar xf cfe-10.0.0.src.tar.xz
+  cd cfe-10.0.0.src/
   mkdir build
   cd build
   cmake .. -DCMAKE_INSTALL_PREFIX=$PREFIX -DCMAKE_PREFIX_PATH=$PREFIX -DCMAKE_BUILD_TYPE=Release
diff --git a/ci/azure/windows_install b/ci/azure/windows_install
index 390467e55..6c2a5442d 100755
--- a/ci/azure/windows_install
+++ b/ci/azure/windows_install
@@ -6,5 +6,5 @@ set -e
 pacman -Su --needed --noconfirm
 pacman -S --needed --noconfirm wget p7zip python3-pip
 pip install s3cmd
-wget -nv "https://ziglang.org/deps/llvm%2bclang-9.0.0-win64-msvc-release.tar.xz"
-tar xf llvm+clang-9.0.0-win64-msvc-release.tar.xz
+wget -nv "https://ziglang.org/deps/llvm%2bclang-10.0.0-win64-msvc-release.tar.xz"
+tar xf llvm+clang-10.0.0-win64-msvc-release.tar.xz
diff --git a/ci/azure/windows_script.bat b/ci/azure/windows_script.bat
index 5c44abcbe..4db80560c 100644
--- a/ci/azure/windows_script.bat
+++ b/ci/azure/windows_script.bat
@@ -11,7 +11,7 @@ SET "MSYSTEM=%PREVMSYSTEM%"
 
 SET "ZIGBUILDDIR=%SRCROOT%\build"
 SET "ZIGINSTALLDIR=%ZIGBUILDDIR%\dist"
-SET "ZIGPREFIXPATH=%SRCROOT%\llvm+clang-9.0.0-win64-msvc-release"
+SET "ZIGPREFIXPATH=%SRCROOT%\llvm+clang-10.0.0-win64-msvc-release"
 
 call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Auxiliary\Build\vcvarsall.bat" x64
 
diff --git a/ci/srht/freebsd_script b/ci/srht/freebsd_script
index 7937efeb3..2e16ca917 100755
--- a/ci/srht/freebsd_script
+++ b/ci/srht/freebsd_script
@@ -4,7 +4,7 @@ set -x
 set -e
 
 ZIGDIR="$(pwd)"
-CACHE_BASENAME="llvm+clang-9.0.0-freebsd-x86_64-release"
+CACHE_BASENAME="llvm+clang-10.0.0-freebsd-x86_64-release"
 PREFIX="$HOME/$CACHE_BASENAME"
 JOBS="-j$(sysctl -n hw.ncpu)"
 
diff --git a/cmake/Findclang.cmake b/cmake/Findclang.cmake
index 704eba981..f5ab755d1 100644
--- a/cmake/Findclang.cmake
+++ b/cmake/Findclang.cmake
@@ -38,10 +38,10 @@ if(MSVC)
 else()
   find_path(CLANG_INCLUDE_DIRS NAMES clang/Frontend/ASTUnit.h
       PATHS
-          /usr/lib/llvm/9/include
-          /usr/lib/llvm-9/include
-          /usr/lib/llvm-9.0/include
-          /usr/local/llvm90/include
+          /usr/lib/llvm/10/include
+          /usr/lib/llvm-10/include
+          /usr/lib/llvm-10.0/include
+          /usr/local/llvm100/include
           /mingw64/include)
 
   macro(FIND_AND_ADD_CLANG_LIB _libname_)
@@ -49,10 +49,10 @@ else()
       find_library(CLANG_${_prettylibname_}_LIB NAMES ${_libname_}
           PATHS
               ${CLANG_LIBDIRS}
-              /usr/lib/llvm/9/lib
-              /usr/lib/llvm-9/lib
-              /usr/lib/llvm-9.0/lib
-              /usr/local/llvm90/lib
+              /usr/lib/llvm/10/lib
+              /usr/lib/llvm-10/lib
+              /usr/lib/llvm-10.0/lib
+              /usr/local/llvm100/lib
               /mingw64/lib
               /c/msys64/mingw64/lib
               c:\\msys64\\mingw64\\lib)
diff --git a/cmake/Findlld.cmake b/cmake/Findlld.cmake
index 878a75015..7f842c046 100644
--- a/cmake/Findlld.cmake
+++ b/cmake/Findlld.cmake
@@ -8,14 +8,14 @@
 
 find_path(LLD_INCLUDE_DIRS NAMES lld/Common/Driver.h
     PATHS
-        /usr/lib/llvm-9.0/include
-        /usr/local/llvm90/include
+        /usr/lib/llvm-10.0/include
+        /usr/local/llvm100/include
         /mingw64/include)
 
-find_library(LLD_LIBRARY NAMES lld-9.0 lld90 lld
+find_library(LLD_LIBRARY NAMES lld-10.0 lld100 lld
     PATHS
-        /usr/lib/llvm-9.0/lib
-        /usr/local/llvm90/lib
+        /usr/lib/llvm-10.0/lib
+        /usr/local/llvm100/lib
 )
 if(EXISTS ${LLD_LIBRARY})
     set(LLD_LIBRARIES ${LLD_LIBRARY})
@@ -24,8 +24,8 @@ else()
         string(TOUPPER ${_libname_} _prettylibname_)
         find_library(LLD_${_prettylibname_}_LIB NAMES ${_libname_}
             PATHS
-                /usr/lib/llvm-9.0/lib
-                /usr/local/llvm90/lib
+                /usr/lib/llvm-10.0/lib
+                /usr/local/llvm100/lib
                 /mingw64/lib
                 /c/msys64/mingw64/lib
                 c:/msys64/mingw64/lib)
diff --git a/cmake/Findllvm.cmake b/cmake/Findllvm.cmake
index 96324a739..095593695 100644
--- a/cmake/Findllvm.cmake
+++ b/cmake/Findllvm.cmake
@@ -8,12 +8,12 @@
 # LLVM_LIBDIRS
 
 find_program(LLVM_CONFIG_EXE
-    NAMES llvm-config-9 llvm-config-9.0 llvm-config90 llvm-config
+    NAMES llvm-config-10 llvm-config-10.0 llvm-config100 llvm-config
     PATHS
         "/mingw64/bin"
         "/c/msys64/mingw64/bin"
         "c:/msys64/mingw64/bin"
-        "C:/Libraries/llvm-9.0.0/bin")
+        "C:/Libraries/llvm-10.0.0/bin")
 
 if ("${LLVM_CONFIG_EXE}" STREQUAL "LLVM_CONFIG_EXE-NOTFOUND")
   message(FATAL_ERROR "unable to find llvm-config")
@@ -28,14 +28,14 @@ execute_process(
 	OUTPUT_VARIABLE LLVM_CONFIG_VERSION
 	OUTPUT_STRIP_TRAILING_WHITESPACE)
 
-if("${LLVM_CONFIG_VERSION}" VERSION_LESS 9)
-  message(FATAL_ERROR "expected LLVM 9.x but found ${LLVM_CONFIG_VERSION}")
+if("${LLVM_CONFIG_VERSION}" VERSION_LESS 10)
+  message(FATAL_ERROR "expected LLVM 10.x but found ${LLVM_CONFIG_VERSION}")
 endif()
-if("${LLVM_CONFIG_VERSION}" VERSION_EQUAL 10)
-  message(FATAL_ERROR "expected LLVM 9.x but found ${LLVM_CONFIG_VERSION}")
+if("${LLVM_CONFIG_VERSION}" VERSION_EQUAL 11)
+  message(FATAL_ERROR "expected LLVM 10.x but found ${LLVM_CONFIG_VERSION}")
 endif()
-if("${LLVM_CONFIG_VERSION}" VERSION_GREATER 10)
-  message(FATAL_ERROR "expected LLVM 9.x but found ${LLVM_CONFIG_VERSION}")
+if("${LLVM_CONFIG_VERSION}" VERSION_GREATER 11)
+  message(FATAL_ERROR "expected LLVM 10.x but found ${LLVM_CONFIG_VERSION}")
 endif()
 
 execute_process(
@@ -113,7 +113,7 @@ execute_process(
 set(LLVM_LIBRARIES ${LLVM_LIBRARIES} ${LLVM_SYSTEM_LIBS})
 
 if(NOT LLVM_LIBRARIES)
-  find_library(LLVM_LIBRARIES NAMES LLVM LLVM-9 LLVM-9.0)
+  find_library(LLVM_LIBRARIES NAMES LLVM LLVM-10 LLVM-10.0)
 endif()
 
 link_directories("${CMAKE_PREFIX_PATH}/lib")
diff --git a/doc/langref.html.in b/doc/langref.html.in
index 1869681d0..d6df886f5 100644
--- a/doc/langref.html.in
+++ b/doc/langref.html.in
@@ -5882,7 +5882,7 @@ volatile (
 // Next is the output constraint string. This feature is still
 // considered unstable in Zig, and so LLVM/GCC documentation
 // must be used to understand the semantics.
-// http://releases.llvm.org/9.0.0/docs/LangRef.html#inline-asm-constraint-string
+// http://releases.llvm.org/10.0.0/docs/LangRef.html#inline-asm-constraint-string
 // https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html
 // In this example, the constraint string means "the result value of
 // this inline assembly instruction is whatever is in $rax".
@@ -5923,7 +5923,7 @@ volatile (
       <p>
       Output constraints are still considered to be unstable in Zig, and
       so
-      <a href="http://releases.llvm.org/9.0.0/docs/LangRef.html#inline-asm-constraint-string">LLVM documentation</a>
+      <a href="http://releases.llvm.org/10.0.0/docs/LangRef.html#inline-asm-constraint-string">LLVM documentation</a>
       and
       <a href="https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html">GCC documentation</a>
       must be used to understand the semantics.
@@ -5938,7 +5938,7 @@ volatile (
       <p>
       Input constraints are still considered to be unstable in Zig, and
       so
-      <a href="http://releases.llvm.org/9.0.0/docs/LangRef.html#inline-asm-constraint-string">LLVM documentation</a>
+      <a href="http://releases.llvm.org/10.0.0/docs/LangRef.html#inline-asm-constraint-string">LLVM documentation</a>
       and
       <a href="https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html">GCC documentation</a>
       must be used to understand the semantics.