diff --git a/eng/build.sh b/eng/build.sh
index 5b55cabd4ba2af..5f297babbf8392 100755
--- a/eng/build.sh
+++ b/eng/build.sh
@@ -18,8 +18,8 @@ usage()
 {
   echo "Common settings:"
   echo "  --subset                   Build a subset, print available subsets with -subset help (short: -s)"
-  echo "  --os                       Build operating system: Windows_NT, Linux, FreeBSD, OSX, tvOS, iOS or Android"
-  echo "  --arch                     Build platform: x86, x64, arm, armel or arm64"
+  echo "  --os                       Build operating system: Windows_NT, Linux, FreeBSD, OSX, tvOS, iOS, Android or WebAssembly"
+  echo "  --arch                     Build platform: x86, x64, arm, armel, arm64 or wasm"
   echo "  --configuration            Build configuration: Debug, Release or [CoreCLR]Checked (short: -c)"
   echo "  --runtimeConfiguration     Runtime build configuration: Debug, Release or [CoreCLR]Checked (short: -rc)"
   echo "  --librariesConfiguration   Libraries build configuration: Debug or Release (short: -lc)"
diff --git a/eng/native/init-distro-rid.sh b/eng/native/init-distro-rid.sh
index 3c875a3e28b96f..9c3491d75664c4 100644
--- a/eng/native/init-distro-rid.sh
+++ b/eng/native/init-distro-rid.sh
@@ -165,6 +165,8 @@ initDistroRidGlobal()
                 distroRid="ios-$buildArch"
             elif [ "$targetOs" = "Android" ]; then
                 distroRid="android-$buildArch"
+            elif [ "$targetOs" = "WebAssembly" ]; then
+                distroRid="wasm-$buildArch"
             elif [ "$targetOs" = "FreeBSD" ]; then
                 distroRid="freebsd-$buildArch"
             elif [ "$targetOs" = "SunOS" ]; then
diff --git a/src/mono/mono.proj b/src/mono/mono.proj
index 8f2ee648712f03..54b95011180553 100644
--- a/src/mono/mono.proj
+++ b/src/mono/mono.proj
@@ -31,6 +31,7 @@
     <XcodeDir Condition="'$(XcodeDir)' == ''">/Applications/Xcode.app/Contents/Developer</XcodeDir>
     <BuildMonoAOTCrossCompiler Condition="'$(TargetsiOS)' == 'true' and '$(TargetsiOSSimulator)' != 'true'">true</BuildMonoAOTCrossCompiler>
     <BuildMonoAOTCrossCompiler Condition="'$(TargetstvOS)' == 'true' and '$(TargetstvOSSimulator)' != 'true'">true</BuildMonoAOTCrossCompiler>
+    <BuildMonoAOTCrossCompiler Condition="'$(TargetsWASM)' == 'true'">true</BuildMonoAOTCrossCompiler>
   </PropertyGroup>
 
   <!-- OSX/iOS/tvOS/Android/Linux Mono runtime build -->
@@ -642,6 +643,40 @@
       <_MonoCFLAGS Include="-fexceptions" />
       <_MonoCXXFLAGS Include="-fexceptions -s DISABLE_EXCEPTION_CATCHING=0" />
       <_MonoAC_VARS Include="ac_cv_func_shm_open_working_with_mmap=no" />
+
+      <!-- AOT cross-compiler configuration -->
+      <_MonoAotCrossConfigureParams Include="--with-core=only" />
+      <_MonoAotCrossConfigureParams Include="--enable-maintainer-mode" />
+      <_MonoAotCrossConfigureParams Include="--enable-compile-warnings" />
+      <_MonoAotCrossConfigureParams Include="--prefix=$(MonoObjDir)cross/out" />
+      <_MonoAotCrossConfigureParams Include="--disable-boehm" />
+      <_MonoAotCrossConfigureParams Include="--disable-btls" />
+      <_MonoAotCrossConfigureParams Include="--disable-iconv" />
+      <_MonoAotCrossConfigureParams Include="--disable-libraries" />
+      <_MonoAotCrossConfigureParams Include="--disable-mcs-build" />
+      <_MonoAotCrossConfigureParams Include="--disable-nls" />
+      <_MonoAotCrossConfigureParams Include="--enable-dtrace=no" />
+      <_MonoAotCrossConfigureParams Include="--enable-icall-symbol-map" />
+      <_MonoAotCrossConfigureParams Include="--enable-minimal=com,remoting" />
+      <_MonoAotCrossConfigureParams Include="--disable-crash-reporting" />
+      <_MonoAotCrossConfigureParams Include="--with-cooperative-gc=no" />
+      <_MonoAotCrossConfigureParams Include="--enable-hybrid-suspend=no" />
+      <_MonoAotCrossConfigureParams Include="--target=wasm32-unknown-none" />
+      <_MonoAotCrossConfigureParams Include="--with-cross-offsets=$(MonoObjDir)cross/offsets-wasm32-unknown-none.h" />
+      <!-- FIXME: LLVM -->
+
+      <_MonoAotCrossCFLAGS Include="-O2" />
+      <_MonoAotCrossCFLAGS Include="-g" />
+      <_MonoAotCrossCFLAGS Include="-m64" />
+
+      <_MonoAotCrossOffsetsToolParams Include="--netcore" />
+      <_MonoAotCrossOffsetsToolParams Include="--abi=wasm32-unknown-unknown" />
+      <_MonoAotCrossOffsetsToolParams Include="--targetdir=&quot;$(MonoObjDir)&quot;" />
+      <_MonoAotCrossOffsetsToolParams Include="--monodir=&quot;$(MonoProjectRoot)&quot;" />
+      <_MonoAotCrossOffsetsToolParams Include="--outfile=&quot;$(MonoObjDir)cross/offsets-wasm32-unknown-none.h&quot;" />
+      <_MonoAotCrossOffsetsToolParams Include="--emscripten-sdk=&quot;$(EMSDK_PATH)/upstream/emscripten&quot;" />
+      <_MonoAotCrossOffsetsToolParams Include="--libclang=&quot;$(EMSDK_PATH)/upstream/lib/libclang.dylib&quot;" Condition="$([MSBuild]::IsOSPlatform('OSX'))" />
+      <_MonoAotCrossOffsetsToolParams Include="--libclang=&quot;$(EMSDK_PATH)/upstream/lib/libclang.so&quot;" Condition="!$([MSBuild]::IsOSPlatform('OSX'))" />
     </ItemGroup>
 
     <!-- Linux options -->
@@ -716,7 +751,7 @@
     <Message Text="--- Building Mono ---" Importance="High" />
     <Exec Condition="'$(TargetsWASM)' != 'true'" Command="make -j$([System.Environment]::ProcessorCount)" IgnoreStandardErrorWarningFormat="true" WorkingDirectory="$(MonoObjDir)" />
     <Exec Condition="'$(TargetsWASM)' == 'true'" Command="bash -c 'source $(EMSDK_PATH)/emsdk_env.sh &amp;&amp; make -j$([System.Environment]::ProcessorCount)'" IgnoreStandardErrorWarningFormat="true" WorkingDirectory="$(MonoObjDir)" />
-    <Exec Condition="'$(TargetstvOS)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetsAndroid)' == 'true'" Command="make install -j$([System.Environment]::ProcessorCount)" IgnoreStandardErrorWarningFormat="true" WorkingDirectory="$(MonoObjDir)" />
+    <Exec Condition="'$(TargetstvOS)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetsAndroid)' == 'true' or '$(TargetsWASM)' == 'true'" Command="make install -j$([System.Environment]::ProcessorCount)" IgnoreStandardErrorWarningFormat="true" WorkingDirectory="$(MonoObjDir)" />
 
     <Message Condition="'$(BuildMonoAOTCrossCompiler)' == 'true'" Text="--- Building Mono AOT cross-compiler ---" Importance="High" />
     <Exec Condition="'$(BuildMonoAOTCrossCompiler)' == 'true'" Command="make -j$([System.Environment]::ProcessorCount)" IgnoreStandardErrorWarningFormat="true" WorkingDirectory="$(MonoObjDir)cross" />
@@ -906,6 +941,7 @@
       <_MonoAotCrossFilePath Condition="'$(TargetsiOS)' == 'true' and '$(Platform)' == 'arm64'">$(MonoObjDir)cross\out\bin\aarch64-darwin-mono-sgen</_MonoAotCrossFilePath>
       <_MonoAotCrossFilePath Condition="'$(TargetsiOS)' == 'true' and '$(Platform)' == 'arm'">$(MonoObjDir)cross\out\bin\arm-darwin-mono-sgen</_MonoAotCrossFilePath>
       <_MonoAotCrossFilePath Condition="'$(TargetstvOS)' == 'true' and '$(Platform)' == 'arm64'">$(MonoObjDir)cross\out\bin\aarch64-darwin-mono-sgen</_MonoAotCrossFilePath>
+      <_MonoAotCrossFilePath Condition="'$(TargetsWASM)' == 'true'">$(MonoObjDir)cross\out\bin\wasm32-unknown-none-mono-sgen</_MonoAotCrossFilePath>
     </PropertyGroup>
 
     <!-- Copy Mono runtime files to artifacts directory -->
@@ -929,7 +965,7 @@
     <Copy SourceFiles="@(_MonoIncludeArtifacts)"
           DestinationFiles="@(_MonoIncludeArtifacts->'$(BinDir)include\%(RecursiveDir)%(Filename)%(Extension)')"
           SkipUnchangedFiles="true"
-          Condition="'$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true' or'$(TargetsAndroid)' == 'true' or '$(TargetsWASM)' == 'true'"/>
+          Condition="'$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true' or '$(TargetsAndroid)' == 'true' or '$(TargetsWASM)' == 'true'"/>
 
     <Exec Condition="'$(TargetsOSX)' == 'true' or '$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true'" Command="install_name_tool -id @rpath/$(MonoFileName) $(BinDir)$(MonoFileName)" />
   </Target>