diff --git a/core/src/main/scala/org/apache/spark/ui/JettyUtils.scala b/core/src/main/scala/org/apache/spark/ui/JettyUtils.scala
index 2a3597e323543..663da0d33e20b 100644
--- a/core/src/main/scala/org/apache/spark/ui/JettyUtils.scala
+++ b/core/src/main/scala/org/apache/spark/ui/JettyUtils.scala
@@ -401,17 +401,13 @@ private[spark] object JettyUtils extends Logging {
       uri.append(rest)
     }
 
-    val rewrittenURI = URI.create(uri.toString())
-    if (query != null) {
-      return new URI(
-          rewrittenURI.getScheme(),
-          rewrittenURI.getAuthority(),
-          rewrittenURI.getPath(),
-          query,
-          rewrittenURI.getFragment()
-        ).normalize()
+    val queryString = if (query == null) {
+      ""
+    } else {
+      s"?$query"
     }
-    rewrittenURI.normalize()
+    // SPARK-33611: use method `URI.create` to avoid percent-encoding twice on the query string.
+    URI.create(uri.toString() + queryString).normalize()
   }
 
   def createProxyLocationHeader(
diff --git a/core/src/test/scala/org/apache/spark/ui/UISuite.scala b/core/src/test/scala/org/apache/spark/ui/UISuite.scala
index 56026eaa0072b..c7e1dfe71d563 100644
--- a/core/src/test/scala/org/apache/spark/ui/UISuite.scala
+++ b/core/src/test/scala/org/apache/spark/ui/UISuite.scala
@@ -216,6 +216,15 @@ class UISuite extends SparkFunSuite {
     assert(rewrittenURI === null)
   }
 
+  test("SPARK-33611: Avoid encoding twice on the query parameter of proxy rewrittenURI") {
+    val prefix = "/worker-id"
+    val target = "http://localhost:8081"
+    val path = "/worker-id/json"
+    val rewrittenURI =
+      JettyUtils.createProxyURI(prefix, target, path, "order%5B0%5D%5Bcolumn%5D=0")
+    assert(rewrittenURI.toString === "http://localhost:8081/json?order%5B0%5D%5Bcolumn%5D=0")
+  }
+
   test("verify rewriting location header for reverse proxy") {
     val clientRequest = mock(classOf[HttpServletRequest])
     var headerValue = "http://localhost:4040/jobs"