diff --git a/packages/react-native-codegen/android/build.gradle b/packages/react-native-codegen/android/build.gradle
index e34e9df6c999de..e84754762c4112 100644
--- a/packages/react-native-codegen/android/build.gradle
+++ b/packages/react-native-codegen/android/build.gradle
@@ -5,6 +5,8 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import org.apache.tools.ant.taskdefs.condition.Os
+
 buildscript {
     repositories {
         mavenLocal()
@@ -42,5 +44,23 @@ task('buildCodegenCLI', type: Exec) {
     nodeModulesDir.mkdirs();
     outputs.dirs(libDir, nodeModulesDir)
 
-    commandLine("$codegenRoot/scripts/oss/build.sh")
+    if (Os.isFamily(Os.FAMILY_WINDOWS)) {
+      // Convert path to Linux format: use canonical path to strip it off relative elements in the middle of the string.
+      // Then replace baskslashes with slashes, remove leading colon, add leading slash.
+      // Eg. D:\path1\sub2/.. -> /D/path1/path2
+      String canonicalPath = new File(codegenRoot).getCanonicalPath()
+      String linuxPath = canonicalPath.replace('\\', '/');
+      linuxPath = linuxPath.replace(':', '')
+      linuxPath = '/' + linuxPath
+
+      // Get the location of bash in the system; assume environment variable created to store it.
+      String bashHome = "$System.env.REACT_WINDOWS_BASH"
+      if (bashHome == null) {
+        throw new GradleException("REACT_WINDOWS_BASH is not defined.")
+      }
+      commandLine(bashHome, "-c", "$linuxPath/scripts/oss/build.sh")
+    }
+    else {
+        commandLine("$codegenRoot/scripts/oss/build.sh")
+    }
 }
diff --git a/packages/react-native-codegen/android/gradlePlugin-build/gradlePlugin/src/main/java/com/facebook/react/codegen/plugin/CodegenPlugin.java b/packages/react-native-codegen/android/gradlePlugin-build/gradlePlugin/src/main/java/com/facebook/react/codegen/plugin/CodegenPlugin.java
index 1d27bf3f8d40ac..dc760c3f17088c 100644
--- a/packages/react-native-codegen/android/gradlePlugin-build/gradlePlugin/src/main/java/com/facebook/react/codegen/plugin/CodegenPlugin.java
+++ b/packages/react-native-codegen/android/gradlePlugin-build/gradlePlugin/src/main/java/com/facebook/react/codegen/plugin/CodegenPlugin.java
@@ -33,6 +33,8 @@ public void apply(final Project project) {
     final File generatedSchemaFile = new File(generatedSrcDir, "schema.json");
 
     // 2. Task: produce schema from JS files.
+    String os = System.getProperty("os.name").toLowerCase();
+
     project
         .getTasks()
         .register(
@@ -62,7 +64,7 @@ public void apply(final Project project) {
 
               ImmutableList<String> execCommands =
                   new ImmutableList.Builder<String>()
-                      .add("yarn")
+                      .add(os.contains("windows") ? "yarn.cmd" : "yarn")
                       .addAll(ImmutableList.copyOf(extension.nodeExecutableAndArgs))
                       .add(extension.codegenGenerateSchemaCLI().getAbsolutePath())
                       .add(generatedSchemaFile.getAbsolutePath())
@@ -96,7 +98,7 @@ public void apply(final Project project) {
 
               ImmutableList<String> execCommands =
                   new ImmutableList.Builder<String>()
-                      .add("yarn")
+                      .add(os.contains("windows") ? "yarn.cmd" : "yarn")
                       .addAll(ImmutableList.copyOf(extension.nodeExecutableAndArgs))
                       .add(extension.codegenGenerateNativeModuleSpecsCLI().getAbsolutePath())
                       .add("android")
diff --git a/packages/react-native-codegen/scripts/oss/build.sh b/packages/react-native-codegen/scripts/oss/build.sh
index 7e22d6bbd6040a..b5913f9f1d6a1e 100755
--- a/packages/react-native-codegen/scripts/oss/build.sh
+++ b/packages/react-native-codegen/scripts/oss/build.sh
@@ -32,12 +32,22 @@ if [[ ${FBSOURCE_ENV:-0} -eq 1 ]]; then
   "$YARN_BINARY" run build
 
   popd >/dev/null
+
 else
   # Run yarn install in a separate tmp dir to avoid conflict with the rest of the repo.
   # Note: OSS-only.
   TMP_DIR=$(mktemp -d)
 
-  cp -R "$CODEGEN_DIR/." "$TMP_DIR"
+  # On Windows this script gets run by a seprate Git Bash instance, which cannot perform the copy
+  # due to file locks created by the host process. Need to exclude .lock files while copying.
+  # Using in-memory tar operation because piping `find` and `grep` doesn't preserve folder structure
+  # during recursive copying, and `rsync` is not installed by default in Git Bash.
+  # As an added benefit, blob copy is faster.
+  if [ "$OSTYPE" = "msys" ] || [ "$OSTYPE" = "cygwin" ]; then
+    tar cf - --exclude='*.lock' "$CODEGEN_DIR" | (cd "$TMP_DIR" && tar xvf - );
+  else
+    cp -R "$CODEGEN_DIR/." "$TMP_DIR";
+  fi
 
   pushd "$TMP_DIR" >/dev/null