diff --git a/.github/workflows/build-icu.yml b/.github/workflows/build-icu.yml
index d3595c9194c..459730c2f71 100644
--- a/.github/workflows/build-icu.yml
+++ b/.github/workflows/build-icu.yml
@@ -28,7 +28,7 @@ jobs:
     name: Build Production Data
     runs-on: ubuntu-latest
     steps:
-      - name: Clone Repository (Custom Ref)
+      - name: Clone CLDR
         uses: actions/checkout@v2
         with:
           ref: ${{ github.event.inputs.cldr-ref }}
@@ -59,14 +59,196 @@ jobs:
       - name: Build prod Data
         run: |
           rm -rf target/cldr-prod
-          mkdir -p target/cldr-prod
+          mkdir -p target/cldr-prod/common
           mvn  -s .github/workflows/mvn-settings.xml -B  -DCLDR_DIR=$(pwd) -DCLDR_GITHUB_ANNOTATIONS=true --file=tools/pom.xml -pl cldr-code  \
             exec:java -Dexec.mainClass=org.unicode.cldr.tool.GenerateProductionData \
-            -Dexec.args="-d target/cldr-prod"
+            -Dexec.args="-d target/cldr-prod/common/"
+          (cd target/cldr-prod/ && zip -r ../cldr-prod.zip *)
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       - name: Upload cldr-prod
         uses: actions/upload-artifact@v2
         with:
           name: cldr-prod
-          path: target/cldr-prod
+          path: target/cldr-prod.zip
+  genicudata:
+    name: Generate ICU4C Data
+    runs-on: ubuntu-latest
+    needs: proddata
+    steps:
+      - name: Download CLDR Production Artifact
+        id: downloadprod
+        uses: actions/download-artifact@v2
+        with:
+          name: cldr-prod
+          path: .
+      - name: Download CLDR tools
+        id: downloadtools
+        uses: actions/download-artifact@v2
+        with:
+          name: cldr-code
+          path: cldr-code
+      - name: Set up JDK 1.8
+        uses: actions/setup-java@v1
+        with:
+          java-version: 1.8
+      - name: Setup Maven Settings
+        uses: s4u/maven-settings-action@v2.4.1
+        with:
+          servers: |
+            [{
+                "id": "github",
+                "username": "${{ github.actor }}",
+                "password": "${{ github.token }}"
+            },{
+                "id": "githubicu",
+                "username": "${{ github.actor }}",
+                "password": "${{ github.token }}"
+            },{
+                "id": "githubcldr",
+                "username": "${{ github.actor }}",
+                "password": "${{ github.token }}"
+            }]
+      - name: Create empty CLDR dir, unpack cldr-prod
+        run: mkdir -p cldr cldr-prod && cd cldr-prod && unzip ../cldr-prod.zip
+      # Don't actually need CLDR
+      # - name: Clone CLDR
+      #   uses: actions/checkout@v2
+      #   with:
+      #     ref: ${{ github.event.inputs.cldr-ref }}
+      #     lfs: false
+      #     repository: ${{ github.event.inputs.cldr-repo }}
+      #     path: cldr
+      - name: Clone ICU
+        uses: actions/checkout@v2
+        with:
+          repository: ${{ github.event.inputs.icu-repo }}
+          ref: ${{ github.event.inputs.icu-ref }}
+          lfs: false # not needed here
+          path: icu
+      - name: Cache local Maven repository
+        uses: actions/cache@v2
+        with:
+          path: ~/.m2/repository
+          key: ${{ runner.os }}-maven-${{ hashFiles('icu/tools/**/pom.xml') }}
+          restore-keys: |
+            ${{ runner.os }}-maven-
+      - name: Install CLDR tools
+        # TODO: Should not have to do this, see ICU-21425
+        # Do this after restoring cache.
+        run: >
+          mvn -B install:install-file   -Dproject.parent.relativePath=""   -DgroupId=org.unicode.cldr
+          -DartifactId=cldr-api   -Dversion=0.1-SNAPSHOT   -Dpackaging=jar   -DgeneratePom=true
+          -Dfile=cldr-code/cldr-code.jar
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      - name: Generate ICU4C Data
+        run: >
+          env
+          TOOLS_ROOT=$(pwd)/icu/tools/
+          CLDR_DIR=$(pwd)/cldr
+          CLDR_DATA_DIR=$(pwd)/cldr-prod/
+          ant -f icu/tools/cldr/cldr-to-icu/build-icu-data.xml clean all && ln icu/icu4c/LICENSE icu/icu4c/source/data/
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      - name: Zip up icu-data.zip
+        run: 'cd icu/icu4c/source && zip -rlq ../../../icu-data.zip data'
+      - name: Upload icu-data.zip
+        uses: actions/upload-artifact@v2
+        with:
+          name: icu-data
+          path: icu-data.zip
+  # clang release build with some options to enforce useful constraints.
+  # Includes dependency checker on an in-source, optimized build.
+  # Includes checking @draft etc. API tags vs. ifndef guards like
+  # U_HIDE_DRAFT_API and U_FORCE_HIDE_DRAFT_API.
+  # (FORCE guards make this tool pass but won't compile to working code.
+  # See the testtagsguards.sh script for details.)
+  icu4c-clang:
+    name: ICU4C Build/Test, Ubuntu/Clang, new data
+    runs-on: ubuntu-latest
+    needs: genicudata
+    steps:
+      - name: Clone ICU
+        uses: actions/checkout@v2
+        with:
+          repository: ${{ github.event.inputs.icu-repo }}
+          ref: ${{ github.event.inputs.icu-ref }}
+          lfs: false
+      - name: Download icu-data.zip
+        uses: actions/download-artifact@v2
+        with:
+          name: icu-data
+          path: .
+      - name: Unpack icu-data.zip
+        run: cd icu4c/source && rm -rf data && unzip -o ../../icu-data.zip
+      - name: ICU4C with clang
+        env:
+          CPPFLAGS: -DU_NO_DEFAULT_INCLUDE_UTF_HEADERS=1
+          CFLAGS: -Wimplicit-fallthrough
+          CXXFLAGS: -Wimplicit-fallthrough
+        run: |
+          sudo apt-get -y install doxygen;
+          cd icu4c/source;
+          ./runConfigureICU Linux;
+          make -j 2;
+          make dist
+      - name: Upload icu4c
+        uses: actions/upload-artifact@v2
+        with:
+          name: icu4c
+          path: icu4c/source/dist
+      - name: ICU4C with clang test
+        env:
+          CPPFLAGS: -DU_NO_DEFAULT_INCLUDE_UTF_HEADERS=1
+          CFLAGS: -Wimplicit-fallthrough
+          CXXFLAGS: -Wimplicit-fallthrough
+        run: |
+          cd icu4c/source;
+          make -j 2 check;
+          ( cd test/depstest && python3 depstest.py ../../../source/ );
+          ( cd .. && source/test/hdrtst/testtagsguards.sh );
+  icu4j-java16:
+    name: ICU4J Build/Test, Java 16, new data
+    runs-on: ubuntu-latest
+    needs: genicudata
+    steps:
+      - name: Clone ICU
+        uses: actions/checkout@v2
+        with:
+          repository: ${{ github.event.inputs.icu-repo }}
+          ref: ${{ github.event.inputs.icu-ref }}
+          lfs: true
+      - name: Checkout lfs objects
+        run: git lfs pull
+      - name: Download icu-data.zip
+        uses: actions/download-artifact@v2
+        with:
+          name: icu-data
+          path: .
+      - name: Unpack icu-data.zip
+        run: cd icu4c/source && rm -rf data && unzip -o ../../icu-data.zip
+      - name: Generate ICU4J data
+        run: cd icu4c/source && ./runConfigureICU Linux && make -j2 && make -C data icu4j-data-install ICU4J_ROOT=$(cd ../../icu4j ; pwd)
+      - uses: actions/setup-java@v1
+        with:
+          java-version: '16'
+      - name: ICU4J Build
+        run: |
+          cd icu4j;
+          ant init;
+          ant jar;
+          ant releaseBinaries;
+      - name: Upload icu4j
+        uses: actions/upload-artifact@v2
+        with:
+          name: icu4j
+          path: icu4j/release
+      - name: ICU4J Test
+        run: |
+          ant check;
+          ant localespiCheck;
+      - name: List failures (if any)
+        run: |
+          [ -d icu4j/out/junit-results ] && cd icu4j && cat `find out/junit-results -name "*.txt" -exec grep -l FAILED {} \;`;
+        if: ${{ failure() }}