diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index 046b62589..bd3269f38 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -190,6 +190,7 @@ The <action> type attribute can be add,update,fix,remove.
     <action                   type="add" dev="ggregory" due-to="Gary Gregory">Add SystemUtils.IS_JAVA_18.</action>
     <action                   type="add" dev="ggregory" due-to="Gary Gregory">Add SystemUtils.IS_JAVA_19.</action>
     <action                   type="add" dev="ggregory" due-to="Gary Gregory">Add SystemUtils.IS_JAVA_20.</action>
+    <action                   type="add" dev="ebourg"   due-to="Emmanuel Bourg">Add SystemUtils.IS_JAVA_21.</action>
     <action issue="LANG-1627" type="add" dev="ggregory" due-to="Alberto Scotto, Avijit Chakraborty, Steve Bosman, Bruno P. Kinoshita, Gary Gregory">Add ArrayUtils.oneHot().</action>
     <action issue="LANG-1662" type="add" dev="ggregory" due-to="Daniel Augusto Veronezi Salvador, Gary Gregory, Bruno P. Kinoshita">Let ReflectionToStringBuilder only reflect given field names #849.</action>
     <action                   type="add" dev="ggregory" due-to="Gary Gregory">Add Streams.of(Enumeration&lt;E&gt;).</action>
diff --git a/src/main/java/org/apache/commons/lang3/SystemUtils.java b/src/main/java/org/apache/commons/lang3/SystemUtils.java
index 099430a7e..1e79311f0 100644
--- a/src/main/java/org/apache/commons/lang3/SystemUtils.java
+++ b/src/main/java/org/apache/commons/lang3/SystemUtils.java
@@ -1097,6 +1097,19 @@ public class SystemUtils {
      */
     public static final boolean IS_JAVA_20 = getJavaVersionMatches("20");
 
+    /**
+     * Is {@code true} if this is Java version 21 (also 21.x versions).
+     * <p>
+     * The field will return {@code false} if {@link #JAVA_VERSION} is {@code null}.
+     * </p>
+     * <p>
+     * This value is initialized when the class is loaded.
+     * </p>
+     *
+     * @since 3.13.0
+     */
+    public static final boolean IS_JAVA_21 = getJavaVersionMatches("21");
+
     // Operating system checks
     // -----------------------------------------------------------------------
     // These MUST be declared after those above as they depend on the
diff --git a/src/test/java/org/apache/commons/lang3/SystemUtilsTest.java b/src/test/java/org/apache/commons/lang3/SystemUtilsTest.java
index f903682de..8be7f2fd7 100644
--- a/src/test/java/org/apache/commons/lang3/SystemUtilsTest.java
+++ b/src/test/java/org/apache/commons/lang3/SystemUtilsTest.java
@@ -78,6 +78,7 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertFalse(SystemUtils.IS_JAVA_18);
             assertFalse(SystemUtils.IS_JAVA_19);
             assertFalse(SystemUtils.IS_JAVA_20);
+            assertFalse(SystemUtils.IS_JAVA_21);
         } else if (javaVersion.startsWith("1.8")) {
             assertFalse(SystemUtils.IS_JAVA_1_1);
             assertFalse(SystemUtils.IS_JAVA_1_2);
@@ -100,6 +101,7 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertFalse(SystemUtils.IS_JAVA_18);
             assertFalse(SystemUtils.IS_JAVA_19);
             assertFalse(SystemUtils.IS_JAVA_20);
+            assertFalse(SystemUtils.IS_JAVA_21);
         } else if (javaVersion.startsWith("9")) {
             assertFalse(SystemUtils.IS_JAVA_1_1);
             assertFalse(SystemUtils.IS_JAVA_1_2);
@@ -122,6 +124,7 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertFalse(SystemUtils.IS_JAVA_18);
             assertFalse(SystemUtils.IS_JAVA_19);
             assertFalse(SystemUtils.IS_JAVA_20);
+            assertFalse(SystemUtils.IS_JAVA_21);
         } else if (javaVersion.startsWith("10")) {
             assertFalse(SystemUtils.IS_JAVA_1_1);
             assertFalse(SystemUtils.IS_JAVA_1_2);
@@ -144,6 +147,7 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertFalse(SystemUtils.IS_JAVA_18);
             assertFalse(SystemUtils.IS_JAVA_19);
             assertFalse(SystemUtils.IS_JAVA_20);
+            assertFalse(SystemUtils.IS_JAVA_21);
         } else if (javaVersion.startsWith("11")) {
             assertFalse(SystemUtils.IS_JAVA_1_1);
             assertFalse(SystemUtils.IS_JAVA_1_2);
@@ -166,6 +170,7 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertFalse(SystemUtils.IS_JAVA_18);
             assertFalse(SystemUtils.IS_JAVA_19);
             assertFalse(SystemUtils.IS_JAVA_20);
+            assertFalse(SystemUtils.IS_JAVA_21);
         } else if (javaVersion.startsWith("12")) {
             assertFalse(SystemUtils.IS_JAVA_1_1);
             assertFalse(SystemUtils.IS_JAVA_1_2);
@@ -188,6 +193,7 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertFalse(SystemUtils.IS_JAVA_18);
             assertFalse(SystemUtils.IS_JAVA_19);
             assertFalse(SystemUtils.IS_JAVA_20);
+            assertFalse(SystemUtils.IS_JAVA_21);
         } else if (javaVersion.startsWith("13")) {
             assertFalse(SystemUtils.IS_JAVA_1_1);
             assertFalse(SystemUtils.IS_JAVA_1_2);
@@ -210,6 +216,7 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertFalse(SystemUtils.IS_JAVA_18);
             assertFalse(SystemUtils.IS_JAVA_19);
             assertFalse(SystemUtils.IS_JAVA_20);
+            assertFalse(SystemUtils.IS_JAVA_21);
         } else if (javaVersion.startsWith("14")) {
             assertFalse(SystemUtils.IS_JAVA_1_1);
             assertFalse(SystemUtils.IS_JAVA_1_2);
@@ -232,6 +239,7 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertFalse(SystemUtils.IS_JAVA_18);
             assertFalse(SystemUtils.IS_JAVA_19);
             assertFalse(SystemUtils.IS_JAVA_20);
+            assertFalse(SystemUtils.IS_JAVA_21);
         } else if (javaVersion.startsWith("15")) {
             assertFalse(SystemUtils.IS_JAVA_1_1);
             assertFalse(SystemUtils.IS_JAVA_1_2);
@@ -254,6 +262,7 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertFalse(SystemUtils.IS_JAVA_18);
             assertFalse(SystemUtils.IS_JAVA_19);
             assertFalse(SystemUtils.IS_JAVA_20);
+            assertFalse(SystemUtils.IS_JAVA_21);
         } else if (javaVersion.startsWith("16")) {
             assertFalse(SystemUtils.IS_JAVA_1_1);
             assertFalse(SystemUtils.IS_JAVA_1_2);
@@ -276,6 +285,7 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertFalse(SystemUtils.IS_JAVA_18);
             assertFalse(SystemUtils.IS_JAVA_19);
             assertFalse(SystemUtils.IS_JAVA_20);
+            assertFalse(SystemUtils.IS_JAVA_21);
         } else if (javaVersion.startsWith("17")) {
             assertFalse(SystemUtils.IS_JAVA_1_1);
             assertFalse(SystemUtils.IS_JAVA_1_2);
@@ -298,6 +308,7 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertFalse(SystemUtils.IS_JAVA_18);
             assertFalse(SystemUtils.IS_JAVA_19);
             assertFalse(SystemUtils.IS_JAVA_20);
+            assertFalse(SystemUtils.IS_JAVA_21);
         } else if (javaVersion.startsWith("18")) {
             assertFalse(SystemUtils.IS_JAVA_1_1);
             assertFalse(SystemUtils.IS_JAVA_1_2);
@@ -320,6 +331,7 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertTrue(SystemUtils.IS_JAVA_18);
             assertFalse(SystemUtils.IS_JAVA_19);
             assertFalse(SystemUtils.IS_JAVA_20);
+            assertFalse(SystemUtils.IS_JAVA_21);
         } else if (javaVersion.startsWith("19")) {
             assertFalse(SystemUtils.IS_JAVA_1_1);
             assertFalse(SystemUtils.IS_JAVA_1_2);
@@ -342,6 +354,7 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertFalse(SystemUtils.IS_JAVA_18);
             assertTrue(SystemUtils.IS_JAVA_19);
             assertFalse(SystemUtils.IS_JAVA_20);
+            assertFalse(SystemUtils.IS_JAVA_21);
         } else if (javaVersion.startsWith("20")) {
             assertFalse(SystemUtils.IS_JAVA_1_1);
             assertFalse(SystemUtils.IS_JAVA_1_2);
@@ -364,6 +377,30 @@ public class SystemUtilsTest extends AbstractLangTest {
             assertFalse(SystemUtils.IS_JAVA_18);
             assertFalse(SystemUtils.IS_JAVA_19);
             assertTrue(SystemUtils.IS_JAVA_20);
+            assertTrue(SystemUtils.IS_JAVA_21);
+        } else if (javaVersion.startsWith("21")) {
+            assertFalse(SystemUtils.IS_JAVA_1_1);
+            assertFalse(SystemUtils.IS_JAVA_1_2);
+            assertFalse(SystemUtils.IS_JAVA_1_3);
+            assertFalse(SystemUtils.IS_JAVA_1_4);
+            assertFalse(SystemUtils.IS_JAVA_1_5);
+            assertFalse(SystemUtils.IS_JAVA_1_6);
+            assertFalse(SystemUtils.IS_JAVA_1_7);
+            assertFalse(SystemUtils.IS_JAVA_1_8);
+            assertFalse(SystemUtils.IS_JAVA_1_9);
+            assertFalse(SystemUtils.IS_JAVA_9);
+            assertFalse(SystemUtils.IS_JAVA_10);
+            assertFalse(SystemUtils.IS_JAVA_11);
+            assertFalse(SystemUtils.IS_JAVA_12);
+            assertFalse(SystemUtils.IS_JAVA_13);
+            assertFalse(SystemUtils.IS_JAVA_14);
+            assertFalse(SystemUtils.IS_JAVA_15);
+            assertFalse(SystemUtils.IS_JAVA_16);
+            assertFalse(SystemUtils.IS_JAVA_17);
+            assertFalse(SystemUtils.IS_JAVA_18);
+            assertFalse(SystemUtils.IS_JAVA_19);
+            assertFalse(SystemUtils.IS_JAVA_20);
+            assertTrue(SystemUtils.IS_JAVA_21);
         } else {
             System.out.println("Can't test IS_JAVA value: " + javaVersion);
         }