diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index ebcb2fa20..c1a58c9f6 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -109,6 +109,8 @@ The <action> type attribute can be add,update,fix,remove.
     <action                   type="fix" dev="ggregory" due-to="Gary Gregory">Deprecate ThreadUtils 0-argument constructor.</action>
     <action                   type="fix" dev="ggregory" due-to="Gary Gregory">Deprecate TypeUtils 0-argument constructor.</action>
     <action                   type="fix" dev="ggregory" due-to="Gary Gregory">Make ArrayFill null-safe.</action>
+    <action                   type="fix" dev="ggregory" due-to="Gary Gregory">Make ArraySorter null-safe.</action>
+    <action                   type="fix" dev="ggregory" due-to="Gary Gregory">Make ArrayUtils.removeAll() null-safe.</action>
     <!-- UPDATE -->
     <action                   type="update" dev="sebb" due-to="Dependabot">Bump commons-parent from 64 to 66.</action>
     <action                   type="update" dev="ggregory" due-to="Dependabot">Bump org.codehaus.mojo:exec-maven-plugin from 3.1.1 to 3.2.0 #1175.</action> 
diff --git a/src/main/java/org/apache/commons/lang3/ArraySorter.java b/src/main/java/org/apache/commons/lang3/ArraySorter.java
index 334e5cae3..7c80c9051 100644
--- a/src/main/java/org/apache/commons/lang3/ArraySorter.java
+++ b/src/main/java/org/apache/commons/lang3/ArraySorter.java
@@ -35,7 +35,9 @@ public class ArraySorter {
      * @see Arrays#sort(byte[])
      */
     public static byte[] sort(final byte[] array) {
-        Arrays.sort(array);
+        if (array != null) {
+            Arrays.sort(array);
+        }
         return array;
     }
 
@@ -47,7 +49,9 @@ public class ArraySorter {
      * @see Arrays#sort(char[])
      */
     public static char[] sort(final char[] array) {
-        Arrays.sort(array);
+        if (array != null) {
+            Arrays.sort(array);
+        }
         return array;
     }
 
@@ -59,7 +63,9 @@ public class ArraySorter {
      * @see Arrays#sort(double[])
      */
     public static double[] sort(final double[] array) {
-        Arrays.sort(array);
+        if (array != null) {
+            Arrays.sort(array);
+        }
         return array;
     }
 
@@ -71,7 +77,9 @@ public class ArraySorter {
      * @see Arrays#sort(float[])
      */
     public static float[] sort(final float[] array) {
-        Arrays.sort(array);
+        if (array != null) {
+            Arrays.sort(array);
+        }
         return array;
     }
 
@@ -83,7 +91,9 @@ public class ArraySorter {
      * @see Arrays#sort(int[])
      */
     public static int[] sort(final int[] array) {
-        Arrays.sort(array);
+        if (array != null) {
+            Arrays.sort(array);
+        }
         return array;
     }
 
@@ -95,7 +105,9 @@ public class ArraySorter {
      * @see Arrays#sort(long[])
      */
     public static long[] sort(final long[] array) {
-        Arrays.sort(array);
+        if (array != null) {
+            Arrays.sort(array);
+        }
         return array;
     }
 
@@ -107,7 +119,9 @@ public class ArraySorter {
      * @see Arrays#sort(short[])
      */
     public static short[] sort(final short[] array) {
-        Arrays.sort(array);
+        if (array != null) {
+            Arrays.sort(array);
+        }
         return array;
     }
 
@@ -120,7 +134,9 @@ public class ArraySorter {
      * @see Arrays#sort(Object[])
      */
     public static <T> T[] sort(final T[] array) {
-        Arrays.sort(array);
+        if (array != null) {
+            Arrays.sort(array);
+        }
         return array;
     }
 
@@ -135,7 +151,9 @@ public class ArraySorter {
      * @see Arrays#sort(Object[])
      */
     public static <T> T[] sort(final T[] array, final Comparator<? super T> comparator) {
-        Arrays.sort(array, comparator);
+        if (array != null) {
+            Arrays.sort(array, comparator);
+        }
         return array;
     }
 
diff --git a/src/main/java/org/apache/commons/lang3/ArrayUtils.java b/src/main/java/org/apache/commons/lang3/ArrayUtils.java
index 93c95b71b..88e690041 100644
--- a/src/main/java/org/apache/commons/lang3/ArrayUtils.java
+++ b/src/main/java/org/apache/commons/lang3/ArrayUtils.java
@@ -5296,6 +5296,9 @@ public class ArrayUtils {
      */
     // package protected for access by unit tests
     static Object removeAll(final Object array, final int... indices) {
+        if (array == null) {
+            return null;
+        }
         final int length = getLength(array);
         int diff = 0; // number of distinct indexes, i.e. number of entries that will be removed
         final int[] clonedIndices = ArraySorter.sort(clone(indices));
@@ -5319,7 +5322,7 @@ public class ArrayUtils {
 
         // create result array
         final Object result = Array.newInstance(array.getClass().getComponentType(), length - diff);
-        if (diff < length) {
+        if (diff < length && clonedIndices != null) {
             int end = length; // index just after last copy
             int dest = length - diff; // number of entries so far not copied
             for (int i = clonedIndices.length - 1; i >= 0; i--) {
diff --git a/src/test/java/org/apache/commons/lang3/ArraySorterTest.java b/src/test/java/org/apache/commons/lang3/ArraySorterTest.java
index d3664321b..b56e0ae8e 100644
--- a/src/test/java/org/apache/commons/lang3/ArraySorterTest.java
+++ b/src/test/java/org/apache/commons/lang3/ArraySorterTest.java
@@ -18,11 +18,15 @@
 package org.apache.commons.lang3;
 
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 import java.util.Arrays;
 
 import org.junit.jupiter.api.Test;
 
+/**
+ * Tests {@link ArraySorter}.
+ */
 public class ArraySorterTest extends AbstractLangTest {
 
     @Test
@@ -31,6 +35,7 @@ public class ArraySorterTest extends AbstractLangTest {
         final byte[] array2 = array1.clone();
         Arrays.sort(array1);
         assertArrayEquals(array1, ArraySorter.sort(array2));
+        assertNull(ArraySorter.sort((byte[]) null));
     }
 
     @Test
@@ -39,6 +44,7 @@ public class ArraySorterTest extends AbstractLangTest {
         final char[] array2 = array1.clone();
         Arrays.sort(array1);
         assertArrayEquals(array1, ArraySorter.sort(array2));
+        assertNull(ArraySorter.sort((char[]) null));
     }
 
     @Test
@@ -47,6 +53,7 @@ public class ArraySorterTest extends AbstractLangTest {
         final String[] array2 = array1.clone();
         Arrays.sort(array1);
         assertArrayEquals(array1, ArraySorter.sort(array2, String::compareTo));
+        assertNull(ArraySorter.sort((String[]) null));
     }
 
     @Test
@@ -55,6 +62,7 @@ public class ArraySorterTest extends AbstractLangTest {
         final double[] array2 = array1.clone();
         Arrays.sort(array1);
         assertArrayEquals(array1, ArraySorter.sort(array2));
+        assertNull(ArraySorter.sort((double[]) null));
     }
 
     @Test
@@ -63,6 +71,7 @@ public class ArraySorterTest extends AbstractLangTest {
         final float[] array2 = array1.clone();
         Arrays.sort(array1);
         assertArrayEquals(array1, ArraySorter.sort(array2));
+        assertNull(ArraySorter.sort((float[]) null));
     }
 
     @Test
@@ -71,6 +80,7 @@ public class ArraySorterTest extends AbstractLangTest {
         final int[] array2 = array1.clone();
         Arrays.sort(array1);
         assertArrayEquals(array1, ArraySorter.sort(array2));
+        assertNull(ArraySorter.sort((int[]) null));
     }
 
     @Test
@@ -79,6 +89,7 @@ public class ArraySorterTest extends AbstractLangTest {
         final long[] array2 = array1.clone();
         Arrays.sort(array1);
         assertArrayEquals(array1, ArraySorter.sort(array2));
+        assertNull(ArraySorter.sort((long[]) null));
     }
 
     @Test
@@ -87,6 +98,7 @@ public class ArraySorterTest extends AbstractLangTest {
         final String[] array2 = array1.clone();
         Arrays.sort(array1);
         assertArrayEquals(array1, ArraySorter.sort(array2));
+        assertNull(ArraySorter.sort((String[]) null));
     }
 
     @Test
@@ -95,6 +107,7 @@ public class ArraySorterTest extends AbstractLangTest {
         final short[] array2 = array1.clone();
         Arrays.sort(array1);
         assertArrayEquals(array1, ArraySorter.sort(array2));
+        assertNull(ArraySorter.sort((short[]) null));
     }
 
 }
diff --git a/src/test/java/org/apache/commons/lang3/ArrayUtilsRemoveMultipleTest.java b/src/test/java/org/apache/commons/lang3/ArrayUtilsRemoveMultipleTest.java
index a5151d015..4b74d9e2d 100644
--- a/src/test/java/org/apache/commons/lang3/ArrayUtilsRemoveMultipleTest.java
+++ b/src/test/java/org/apache/commons/lang3/ArrayUtilsRemoveMultipleTest.java
@@ -26,10 +26,12 @@ import static org.junit.jupiter.api.Assertions.assertThrows;
 import org.junit.jupiter.api.Test;
 
 /**
- * Tests ArrayUtils remove and removeElement methods.
+ * Tests {@link ArrayUtils} remove and removeElement methods.
  */
 public class ArrayUtilsRemoveMultipleTest extends AbstractLangTest {
 
+    private static final int[] NULL_INDICES = null;
+
     @Test
     public void testRemoveAllBooleanArray() {
         boolean[] array;
@@ -550,47 +552,110 @@ public class ArrayUtilsRemoveMultipleTest extends AbstractLangTest {
 
     @Test
     public void testRemoveAllNullBooleanArray() {
-        assertThrows(IndexOutOfBoundsException.class, () -> ArrayUtils.removeAll((boolean[]) null, 0));
+        assertNull(ArrayUtils.removeAll((boolean[]) null, 0));
+        assertNull(ArrayUtils.removeAll((boolean[]) null, NULL_INDICES));
+        final boolean[] array0 = {};
+        assertArrayEquals(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        assertNotSame(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        final boolean[] array1 = new boolean[1];
+        assertArrayEquals(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
+        assertNotSame(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
     }
 
     @Test
     public void testRemoveAllNullByteArray() {
-        assertThrows(IndexOutOfBoundsException.class, () -> ArrayUtils.removeAll((byte[]) null, 0));
+        assertNull(ArrayUtils.removeAll((byte[]) null, 0));
+        assertNull(ArrayUtils.removeAll((byte[]) null, NULL_INDICES));
+        final byte[] array0 = {};
+        assertArrayEquals(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        assertNotSame(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        final byte[] array1 = new byte[1];
+        assertArrayEquals(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
+        assertNotSame(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
     }
 
     @Test
     public void testRemoveAllNullCharArray() {
-        assertThrows(IndexOutOfBoundsException.class, () -> ArrayUtils.removeAll((char[]) null, 0));
+        assertNull(ArrayUtils.removeAll((char[]) null, 0));
+        assertNull(ArrayUtils.removeAll((char[]) null, NULL_INDICES));
+        final char[] array0 = {};
+        assertArrayEquals(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        assertNotSame(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        final char[] array1 = new char[1];
+        assertArrayEquals(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
+        assertNotSame(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
     }
 
     @Test
     public void testRemoveAllNullDoubleArray() {
-        assertThrows(IndexOutOfBoundsException.class, () -> ArrayUtils.removeAll((double[]) null, 0));
+        assertNull(ArrayUtils.removeAll((double[]) null, 0));
+        assertNull(ArrayUtils.removeAll((double[]) null, NULL_INDICES));
+        final double[] array0 = {};
+        assertArrayEquals(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        assertNotSame(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        final double[] array1 = new double[1];
+        assertArrayEquals(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
+        assertNotSame(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
     }
 
     @Test
     public void testRemoveAllNullFloatArray() {
-        assertThrows(IndexOutOfBoundsException.class, () -> ArrayUtils.removeAll((float[]) null, 0));
+        assertNull(ArrayUtils.removeAll((float[]) null, 0));
+        assertNull(ArrayUtils.removeAll((float[]) null, NULL_INDICES));
+        final float[] array0 = {};
+        assertArrayEquals(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        assertNotSame(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        final float[] array1 = new float[1];
+        assertArrayEquals(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
+        assertNotSame(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
     }
 
     @Test
     public void testRemoveAllNullIntArray() {
-        assertThrows(IndexOutOfBoundsException.class, () -> ArrayUtils.removeAll((int[]) null, 0));
+        assertNull(ArrayUtils.removeAll((int[]) null, 0));
+        assertNull(ArrayUtils.removeAll((int[]) null, NULL_INDICES));
+        final int[] array0 = {};
+        assertArrayEquals(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        assertNotSame(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        final int[] array1 = new int[1];
+        assertArrayEquals(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
+        assertNotSame(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
     }
 
     @Test
     public void testRemoveAllNullLongArray() {
-        assertThrows(IndexOutOfBoundsException.class, () -> ArrayUtils.removeAll((long[]) null, 0));
+        assertNull(ArrayUtils.removeAll((long[]) null, 0));
+        assertNull(ArrayUtils.removeAll((long[]) null, NULL_INDICES));
+        final long[] array0 = {};
+        assertArrayEquals(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        assertNotSame(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        final long[] array1 = new long[1];
+        assertArrayEquals(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
+        assertNotSame(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
     }
 
     @Test
     public void testRemoveAllNullObjectArray() {
-        assertThrows(IndexOutOfBoundsException.class, () -> ArrayUtils.remove((Object[]) null, 0));
+        assertNull(ArrayUtils.removeAll((Object[]) null, 0));
+        assertNull(ArrayUtils.removeAll((Object[]) null, NULL_INDICES));
+        final Object[] array0 = {};
+        assertArrayEquals(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        assertNotSame(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        final Object[] array1 = new Object[1];
+        assertArrayEquals(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
+        assertNotSame(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
     }
 
     @Test
     public void testRemoveAllNullShortArray() {
-        assertThrows(IndexOutOfBoundsException.class, () -> ArrayUtils.removeAll((short[]) null, 0));
+        assertNull(ArrayUtils.removeAll((short[]) null, 0));
+        assertNull(ArrayUtils.removeAll((short[]) null, NULL_INDICES));
+        final short[] array0 = {};
+        assertArrayEquals(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        assertNotSame(array0, ArrayUtils.removeAll(array0, NULL_INDICES));
+        final short[] array1 = new short[1];
+        assertArrayEquals(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
+        assertNotSame(array1, ArrayUtils.removeAll(array1, NULL_INDICES));
     }
 
     @Test
@@ -953,34 +1018,34 @@ public class ArrayUtilsRemoveMultipleTest extends AbstractLangTest {
         assertArrayEquals(new double[]{2, 1}, array);
         assertEquals(Double.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements((double[]) null, (double) 1, (double) 2);
+        array = ArrayUtils.removeElements((double[]) null, 1, 2);
         assertNull(array);
 
-        array = ArrayUtils.removeElements(ArrayUtils.EMPTY_DOUBLE_ARRAY, (double) 1, (double) 2);
+        array = ArrayUtils.removeElements(ArrayUtils.EMPTY_DOUBLE_ARRAY, 1, 2);
         assertArrayEquals(ArrayUtils.EMPTY_DOUBLE_ARRAY, array);
         assertEquals(Double.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements(new double[] { 1 }, (double) 1, (double) 2);
+        array = ArrayUtils.removeElements(new double[] { 1 }, 1, 2);
         assertArrayEquals(ArrayUtils.EMPTY_DOUBLE_ARRAY, array);
         assertEquals(Double.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements(new double[] { 1, 2 }, (double) 1, (double) 2);
+        array = ArrayUtils.removeElements(new double[] { 1, 2 }, 1, 2);
         assertArrayEquals(ArrayUtils.EMPTY_DOUBLE_ARRAY, array);
         assertEquals(Double.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements(new double[] { 1, 2 }, (double) 1, (double) 1);
+        array = ArrayUtils.removeElements(new double[] { 1, 2 }, 1, 1);
         assertArrayEquals(new double[]{2}, array);
         assertEquals(Double.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements(new double[] { 1, 2, 1 }, (double) 1, (double) 2);
+        array = ArrayUtils.removeElements(new double[] { 1, 2, 1 }, 1, 2);
         assertArrayEquals(new double[]{1}, array);
         assertEquals(Double.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements(new double[] { 1, 2, 1 }, (double) 1, (double) 1);
+        array = ArrayUtils.removeElements(new double[] { 1, 2, 1 }, 1, 1);
         assertArrayEquals(new double[]{2}, array);
         assertEquals(Double.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements(new double[] { 1, 2, 1 }, (double) 1, (double) 1, (double) 1, (double) 1);
+        array = ArrayUtils.removeElements(new double[] { 1, 2, 1 }, 1, 1, 1, 1);
         assertArrayEquals(new double[]{2}, array);
         assertEquals(Double.TYPE, array.getClass().getComponentType());
     }
@@ -1009,34 +1074,34 @@ public class ArrayUtilsRemoveMultipleTest extends AbstractLangTest {
         assertArrayEquals(new float[]{2, 1}, array);
         assertEquals(Float.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements((float[]) null, (float) 1, (float) 1);
+        array = ArrayUtils.removeElements((float[]) null, 1, 1);
         assertNull(array);
 
-        array = ArrayUtils.removeElements(ArrayUtils.EMPTY_FLOAT_ARRAY, (float) 1, (float) 1);
+        array = ArrayUtils.removeElements(ArrayUtils.EMPTY_FLOAT_ARRAY, 1, 1);
         assertArrayEquals(ArrayUtils.EMPTY_FLOAT_ARRAY, array);
         assertEquals(Float.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements(new float[] { 1 }, (float) 1, (float) 1);
+        array = ArrayUtils.removeElements(new float[] { 1 }, 1, 1);
         assertArrayEquals(ArrayUtils.EMPTY_FLOAT_ARRAY, array);
         assertEquals(Float.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements(new float[] { 1, 2 }, (float) 1, (float) 2);
+        array = ArrayUtils.removeElements(new float[] { 1, 2 }, 1, 2);
         assertArrayEquals(ArrayUtils.EMPTY_FLOAT_ARRAY, array);
         assertEquals(Float.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements(new float[] { 1, 2 }, (float) 1, (float) 1);
+        array = ArrayUtils.removeElements(new float[] { 1, 2 }, 1, 1);
         assertArrayEquals(new float[]{2}, array);
         assertEquals(Float.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements(new float[] { 1, 2, 1 }, (float) 1, (float) 1);
+        array = ArrayUtils.removeElements(new float[] { 1, 2, 1 }, 1, 1);
         assertArrayEquals(new float[]{2}, array);
         assertEquals(Float.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements(new float[] { 1, 2, 1 }, (float) 1, (float) 2);
+        array = ArrayUtils.removeElements(new float[] { 1, 2, 1 }, 1, 2);
         assertArrayEquals(new float[]{1}, array);
         assertEquals(Float.TYPE, array.getClass().getComponentType());
 
-        array = ArrayUtils.removeElements(new float[] { 1, 2, 1 }, (float) 1, (float) 1, (float) 1, (float) 1);
+        array = ArrayUtils.removeElements(new float[] { 1, 2, 1 }, 1, 1, 1, 1);
         assertArrayEquals(new float[]{2}, array);
         assertEquals(Float.TYPE, array.getClass().getComponentType());
     }