diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 798bdb737a..ab3626d4b1 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -87,6 +87,8 @@
         `StaticOverlaySettings`. `OverlaySettings` can be subclassed to allow
         dynamic overlay settings.
 *   Muxers:
+    *   Moved `MuxerException` out of `Muxer` interface to avoid a very long
+        fully qualified name.
 *   IMA extension:
 *   Session:
     *   Add 'Context' as a parameter to
diff --git a/libraries/muxer/src/androidTest/java/androidx/media3/muxer/AndroidMuxerTestUtil.java b/libraries/muxer/src/androidTest/java/androidx/media3/muxer/AndroidMuxerTestUtil.java
index d5fa79ebf0..14a1d62bc0 100644
--- a/libraries/muxer/src/androidTest/java/androidx/media3/muxer/AndroidMuxerTestUtil.java
+++ b/libraries/muxer/src/androidTest/java/androidx/media3/muxer/AndroidMuxerTestUtil.java
@@ -20,7 +20,6 @@ import android.content.res.AssetFileDescriptor;
 import android.media.MediaCodec;
 import androidx.media3.common.util.MediaFormatUtil;
 import androidx.media3.exoplayer.MediaExtractorCompat;
-import androidx.media3.muxer.Muxer.MuxerException;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
diff --git a/libraries/muxer/src/main/java/androidx/media3/muxer/Muxer.java b/libraries/muxer/src/main/java/androidx/media3/muxer/Muxer.java
index 0455ed53f5..f171601232 100644
--- a/libraries/muxer/src/main/java/androidx/media3/muxer/Muxer.java
+++ b/libraries/muxer/src/main/java/androidx/media3/muxer/Muxer.java
@@ -18,7 +18,6 @@ package androidx.media3.muxer;
 import android.media.MediaCodec.BufferInfo;
 import androidx.media3.common.C;
 import androidx.media3.common.Format;
-import androidx.media3.common.MediaLibraryInfo;
 import androidx.media3.common.Metadata;
 import androidx.media3.common.MimeTypes;
 import androidx.media3.common.util.UnstableApi;
@@ -28,24 +27,6 @@ import java.nio.ByteBuffer;
 /** The muxer for producing media container files. */
 @UnstableApi
 public interface Muxer {
-  /** Thrown when a muxer failure occurs. */
-  final class MuxerException extends Exception {
-
-    static {
-      MediaLibraryInfo.registerModule("media3.muxer");
-    }
-
-    /**
-     * Creates an instance.
-     *
-     * @param message See {@link #getMessage()}.
-     * @param cause See {@link #getCause()}.
-     */
-    public MuxerException(String message, Throwable cause) {
-      super(message, cause);
-    }
-  }
-
   /** Factory for muxers. */
   interface Factory {
     /**
diff --git a/libraries/muxer/src/main/java/androidx/media3/muxer/MuxerException.java b/libraries/muxer/src/main/java/androidx/media3/muxer/MuxerException.java
new file mode 100644
index 0000000000..4ea28a8ce9
--- /dev/null
+++ b/libraries/muxer/src/main/java/androidx/media3/muxer/MuxerException.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package androidx.media3.muxer;
+
+import androidx.media3.common.MediaLibraryInfo;
+import androidx.media3.common.util.UnstableApi;
+
+/** Thrown when a muxer failure occurs. */
+@UnstableApi
+public final class MuxerException extends Exception {
+
+  static {
+    MediaLibraryInfo.registerModule("media3.muxer");
+  }
+
+  /**
+   * Creates an instance.
+   *
+   * @param message See {@link #getMessage()}.
+   * @param cause See {@link #getCause()}.
+   */
+  public MuxerException(String message, Throwable cause) {
+    super(message, cause);
+  }
+}
diff --git a/libraries/muxer/src/test/java/androidx/media3/muxer/Mp4MuxerEndToEndTest.java b/libraries/muxer/src/test/java/androidx/media3/muxer/Mp4MuxerEndToEndTest.java
index 06fdf22307..75c0eb19be 100644
--- a/libraries/muxer/src/test/java/androidx/media3/muxer/Mp4MuxerEndToEndTest.java
+++ b/libraries/muxer/src/test/java/androidx/media3/muxer/Mp4MuxerEndToEndTest.java
@@ -815,7 +815,7 @@ public class Mp4MuxerEndToEndTest {
   }
 
   private static void writeFakeSamples(Mp4Muxer muxer, TrackToken trackToken, int sampleCount)
-      throws Muxer.MuxerException {
+      throws MuxerException {
     for (int i = 0; i < sampleCount; i++) {
       Pair<ByteBuffer, BufferInfo> sampleAndSampleInfo =
           getFakeSampleAndSampleInfo(/* presentationTimeUs= */ i);
diff --git a/libraries/transformer/src/androidTest/java/androidx/media3/transformer/TransformerPauseResumeTest.java b/libraries/transformer/src/androidTest/java/androidx/media3/transformer/TransformerPauseResumeTest.java
index ced76636fb..90105893e1 100644
--- a/libraries/transformer/src/androidTest/java/androidx/media3/transformer/TransformerPauseResumeTest.java
+++ b/libraries/transformer/src/androidTest/java/androidx/media3/transformer/TransformerPauseResumeTest.java
@@ -36,7 +36,7 @@ import androidx.media3.common.audio.SonicAudioProcessor;
 import androidx.media3.common.util.Util;
 import androidx.media3.effect.RgbFilter;
 import androidx.media3.muxer.Muxer;
-import androidx.media3.muxer.Muxer.MuxerException;
+import androidx.media3.muxer.MuxerException;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.platform.app.InstrumentationRegistry;
 import com.google.common.base.Ascii;
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/DefaultMuxer.java b/libraries/transformer/src/main/java/androidx/media3/transformer/DefaultMuxer.java
index 5dadcece91..6a338ac71a 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/DefaultMuxer.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/DefaultMuxer.java
@@ -22,6 +22,7 @@ import androidx.media3.common.Metadata;
 import androidx.media3.common.util.UnstableApi;
 import androidx.media3.common.util.Util;
 import androidx.media3.muxer.Muxer;
+import androidx.media3.muxer.MuxerException;
 import com.google.common.collect.ImmutableList;
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.nio.ByteBuffer;
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/FrameworkMuxer.java b/libraries/transformer/src/main/java/androidx/media3/transformer/FrameworkMuxer.java
index 7ba51ed585..20b3ed8c7c 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/FrameworkMuxer.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/FrameworkMuxer.java
@@ -34,6 +34,7 @@ import androidx.media3.common.util.MediaFormatUtil;
 import androidx.media3.common.util.Util;
 import androidx.media3.container.Mp4LocationData;
 import androidx.media3.muxer.Muxer;
+import androidx.media3.muxer.MuxerException;
 import com.google.common.collect.ImmutableList;
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/InAppMuxer.java b/libraries/transformer/src/main/java/androidx/media3/transformer/InAppMuxer.java
index ab01b2e1de..5d7ef25b54 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/InAppMuxer.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/InAppMuxer.java
@@ -31,6 +31,7 @@ import androidx.media3.container.Mp4OrientationData;
 import androidx.media3.muxer.FragmentedMp4Muxer;
 import androidx.media3.muxer.Mp4Muxer;
 import androidx.media3.muxer.Muxer;
+import androidx.media3.muxer.MuxerException;
 import androidx.media3.muxer.MuxerUtil;
 import com.google.common.collect.ImmutableList;
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/MuxerWrapper.java b/libraries/transformer/src/main/java/androidx/media3/transformer/MuxerWrapper.java
index 9f06756cda..01283632ba 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/MuxerWrapper.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/MuxerWrapper.java
@@ -48,8 +48,8 @@ import androidx.media3.common.util.Util;
 import androidx.media3.container.NalUnitUtil;
 import androidx.media3.effect.DebugTraceUtil;
 import androidx.media3.muxer.Muxer;
-import androidx.media3.muxer.Muxer.MuxerException;
 import androidx.media3.muxer.Muxer.TrackToken;
+import androidx.media3.muxer.MuxerException;
 import com.google.common.collect.ImmutableList;
 import java.io.File;
 import java.lang.annotation.Documented;
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/SampleExporter.java b/libraries/transformer/src/main/java/androidx/media3/transformer/SampleExporter.java
index 33be1e3309..3dc5993802 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/SampleExporter.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/SampleExporter.java
@@ -31,7 +31,7 @@ import androidx.media3.common.Format;
 import androidx.media3.common.Metadata;
 import androidx.media3.common.MimeTypes;
 import androidx.media3.decoder.DecoderInputBuffer;
-import androidx.media3.muxer.Muxer.MuxerException;
+import androidx.media3.muxer.MuxerException;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import java.util.List;
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerInternal.java b/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerInternal.java
index f9cf879912..f1fc33e90b 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerInternal.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerInternal.java
@@ -65,7 +65,7 @@ import androidx.media3.common.util.ConditionVariable;
 import androidx.media3.common.util.HandlerWrapper;
 import androidx.media3.common.util.Util;
 import androidx.media3.effect.DebugTraceUtil;
-import androidx.media3.muxer.Muxer.MuxerException;
+import androidx.media3.muxer.MuxerException;
 import androidx.media3.transformer.AssetLoader.CompositionSettings;
 import com.google.common.collect.ImmutableList;
 import java.lang.annotation.Documented;
diff --git a/libraries/transformer/src/test/java/androidx/media3/transformer/CapturingMuxer.java b/libraries/transformer/src/test/java/androidx/media3/transformer/CapturingMuxer.java
index 4961a0cb40..ed0868548b 100644
--- a/libraries/transformer/src/test/java/androidx/media3/transformer/CapturingMuxer.java
+++ b/libraries/transformer/src/test/java/androidx/media3/transformer/CapturingMuxer.java
@@ -27,6 +27,7 @@ import androidx.media3.common.Format;
 import androidx.media3.common.Metadata;
 import androidx.media3.common.util.Util;
 import androidx.media3.muxer.Muxer;
+import androidx.media3.muxer.MuxerException;
 import androidx.media3.test.utils.DumpableFormat;
 import androidx.media3.test.utils.Dumper;
 import androidx.media3.test.utils.Dumper.Dumpable;
diff --git a/libraries/transformer/src/test/java/androidx/media3/transformer/MuxerWrapperTest.java b/libraries/transformer/src/test/java/androidx/media3/transformer/MuxerWrapperTest.java
index c1aa9032e0..a3c663da37 100644
--- a/libraries/transformer/src/test/java/androidx/media3/transformer/MuxerWrapperTest.java
+++ b/libraries/transformer/src/test/java/androidx/media3/transformer/MuxerWrapperTest.java
@@ -30,7 +30,7 @@ import androidx.annotation.Nullable;
 import androidx.media3.common.C;
 import androidx.media3.common.ColorInfo;
 import androidx.media3.common.Format;
-import androidx.media3.muxer.Muxer.MuxerException;
+import androidx.media3.muxer.MuxerException;
 import androidx.media3.test.utils.DumpFileAsserts;
 import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;