diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ShadowNodeRegistry.java b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ShadowNodeRegistry.java
deleted file mode 100644
index a2a286f9e1d..00000000000
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ShadowNodeRegistry.java
+++ /dev/null
@@ -1,96 +0,0 @@
-/*
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-package com.facebook.react.uimanager;
-
-import android.util.SparseArray;
-import android.util.SparseBooleanArray;
-import android.view.View;
-import com.facebook.react.common.SingleThreadAsserter;
-import com.facebook.react.common.annotations.internal.LegacyArchitecture;
-import com.facebook.react.common.annotations.internal.LegacyArchitectureLogLevel;
-import com.facebook.react.common.annotations.internal.LegacyArchitectureLogger;
-
-/**
- * Simple container class to keep track of {@link ReactShadowNode}s associated with a particular
- * UIManagerModule instance.
- */
-@LegacyArchitecture
-class ShadowNodeRegistry {
-
-  static {
-    LegacyArchitectureLogger.assertWhenLegacyArchitectureMinifyingEnabled(
-        "ShadowNodeRegistry", LegacyArchitectureLogLevel.WARNING);
-  }
-
-  private final SparseArray<ReactShadowNode> mTagsToCSSNodes;
-  private final SparseBooleanArray mRootTags;
-  private final SingleThreadAsserter mThreadAsserter;
-
-  public ShadowNodeRegistry() {
-    mTagsToCSSNodes = new SparseArray<>();
-    mRootTags = new SparseBooleanArray();
-    mThreadAsserter = new SingleThreadAsserter();
-  }
-
-  public void addRootNode(ReactShadowNode node) {
-    mThreadAsserter.assertNow();
-    int tag = node.getReactTag();
-    mTagsToCSSNodes.put(tag, node);
-    mRootTags.put(tag, true);
-  }
-
-  public void removeRootNode(int tag) {
-    mThreadAsserter.assertNow();
-    if (tag == View.NO_ID) {
-      // This root node has already been removed (likely due to a threading issue caused by async js
-      // execution). Ignore this root removal.
-      return;
-    }
-    if (!mRootTags.get(tag)) {
-      throw new IllegalViewOperationException(
-          "View with tag " + tag + " is not registered as a root view");
-    }
-
-    mTagsToCSSNodes.remove(tag);
-    mRootTags.delete(tag);
-  }
-
-  public void addNode(ReactShadowNode node) {
-    mThreadAsserter.assertNow();
-    mTagsToCSSNodes.put(node.getReactTag(), node);
-  }
-
-  public void removeNode(int tag) {
-    mThreadAsserter.assertNow();
-    if (mRootTags.get(tag)) {
-      throw new IllegalViewOperationException(
-          "Trying to remove root node " + tag + " without using removeRootNode!");
-    }
-    mTagsToCSSNodes.remove(tag);
-  }
-
-  public ReactShadowNode getNode(int tag) {
-    mThreadAsserter.assertNow();
-    return mTagsToCSSNodes.get(tag);
-  }
-
-  public boolean isRootNode(int tag) {
-    mThreadAsserter.assertNow();
-    return mRootTags.get(tag);
-  }
-
-  public int getRootNodeCount() {
-    mThreadAsserter.assertNow();
-    return mRootTags.size();
-  }
-
-  public int getRootTag(int index) {
-    mThreadAsserter.assertNow();
-    return mRootTags.keyAt(index);
-  }
-}
diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ShadowNodeRegistry.kt b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ShadowNodeRegistry.kt
new file mode 100644
index 00000000000..d7ade8a4be7
--- /dev/null
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ShadowNodeRegistry.kt
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.uimanager
+
+import android.util.SparseArray
+import android.util.SparseBooleanArray
+import android.view.View
+import com.facebook.react.common.SingleThreadAsserter
+import com.facebook.react.common.annotations.internal.LegacyArchitecture
+import com.facebook.react.common.annotations.internal.LegacyArchitectureLogLevel
+import com.facebook.react.common.annotations.internal.LegacyArchitectureLogger
+
+/**
+ * Simple container class to keep track of [ReactShadowNode]s associated with a particular
+ * UIManagerModule instance.
+ */
+@LegacyArchitecture
+internal class ShadowNodeRegistry {
+  private val tagsToCSSNodes = SparseArray<ReactShadowNode<*>>()
+  private val rootTags = SparseBooleanArray()
+  private val threadAsserter = SingleThreadAsserter()
+
+  fun addRootNode(node: ReactShadowNode<*>) {
+    threadAsserter.assertNow()
+    val tag = node.reactTag
+    tagsToCSSNodes.put(tag, node)
+    rootTags.put(tag, true)
+  }
+
+  fun removeRootNode(tag: Int) {
+    threadAsserter.assertNow()
+    if (tag == View.NO_ID) {
+      // This root node has already been removed (likely due to a threading issue caused by async js
+      // execution). Ignore this root removal.
+      return
+    }
+    if (!rootTags[tag]) {
+      throw IllegalViewOperationException("View with tag $tag is not registered as a root view")
+    }
+
+    tagsToCSSNodes.remove(tag)
+    rootTags.delete(tag)
+  }
+
+  fun addNode(node: ReactShadowNode<*>) {
+    threadAsserter.assertNow()
+    tagsToCSSNodes.put(node.reactTag, node)
+  }
+
+  fun removeNode(tag: Int) {
+    threadAsserter.assertNow()
+    if (rootTags[tag]) {
+      throw IllegalViewOperationException(
+          "Trying to remove root node $tag without using removeRootNode!")
+    }
+    tagsToCSSNodes.remove(tag)
+  }
+
+  fun getNode(tag: Int): ReactShadowNode<*>? {
+    threadAsserter.assertNow()
+    return tagsToCSSNodes[tag]
+  }
+
+  fun isRootNode(tag: Int): Boolean {
+    threadAsserter.assertNow()
+    return rootTags[tag]
+  }
+
+  val rootNodeCount: Int
+    get() {
+      threadAsserter.assertNow()
+      return rootTags.size()
+    }
+
+  fun getRootTag(index: Int): Int {
+    threadAsserter.assertNow()
+    return rootTags.keyAt(index)
+  }
+
+  private companion object {
+    init {
+      LegacyArchitectureLogger.assertWhenLegacyArchitectureMinifyingEnabled(
+          "ShadowNodeRegistry", LegacyArchitectureLogLevel.WARNING)
+    }
+  }
+}