diff --git a/icu4j/main/classes/core/src/com/ibm/icu/text/Normalizer2.java b/icu4j/main/classes/core/src/com/ibm/icu/text/Normalizer2.java
index 4857bfd4475..5fb5ded49ea 100644
--- a/icu4j/main/classes/core/src/com/ibm/icu/text/Normalizer2.java
+++ b/icu4j/main/classes/core/src/com/ibm/icu/text/Normalizer2.java
@@ -204,7 +204,17 @@ public abstract class Normalizer2 {
      * @stable ICU 4.4
      */
     public String normalize(CharSequence src) {
-        return normalize(src, new StringBuilder()).toString();
+        if(src instanceof String) {
+            // Fastpath: Do not construct a new String if the src is a String
+            // and is already normalized.
+            int spanLength=spanQuickCheckYes(src);
+            if(spanLength==src.length()) {
+                return (String)src;
+            }
+            StringBuilder sb=new StringBuilder(src.length()).append(src, 0, spanLength);
+            return normalizeSecondAndAppend(sb, src.subSequence(spanLength, src.length())).toString();
+        }
+        return normalize(src, new StringBuilder(src.length())).toString();
     }
 
     /**