diff --git a/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSessionCatalog.scala b/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSessionCatalog.scala
index 29585acd4759a..73ae66c09c56c 100644
--- a/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSessionCatalog.scala
+++ b/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSessionCatalog.scala
@@ -36,7 +36,7 @@ import org.apache.spark.sql.catalyst.parser.ParserInterface
 import org.apache.spark.sql.hive.HiveShim.HiveFunctionWrapper
 import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.types.{DecimalType, DoubleType}
-
+import org.apache.spark.util.Utils
 
 private[sql] class HiveSessionCatalog(
     externalCatalogBuilder: () => ExternalCatalog,
@@ -65,49 +65,52 @@ private[sql] class HiveSessionCatalog(
       name: String,
       clazz: Class[_],
       input: Seq[Expression]): Expression = {
-
-    Try(super.makeFunctionExpression(name, clazz, input)).getOrElse {
-      var udfExpr: Option[Expression] = None
-      try {
-        // When we instantiate hive UDF wrapper class, we may throw exception if the input
-        // expressions don't satisfy the hive UDF, such as type mismatch, input number
-        // mismatch, etc. Here we catch the exception and throw AnalysisException instead.
-        if (classOf[UDF].isAssignableFrom(clazz)) {
-          udfExpr = Some(HiveSimpleUDF(name, new HiveFunctionWrapper(clazz.getName), input))
-          udfExpr.get.dataType // Force it to check input data types.
-        } else if (classOf[GenericUDF].isAssignableFrom(clazz)) {
-          udfExpr = Some(HiveGenericUDF(name, new HiveFunctionWrapper(clazz.getName), input))
-          udfExpr.get.dataType // Force it to check input data types.
-        } else if (classOf[AbstractGenericUDAFResolver].isAssignableFrom(clazz)) {
-          udfExpr = Some(HiveUDAFFunction(name, new HiveFunctionWrapper(clazz.getName), input))
-          udfExpr.get.dataType // Force it to check input data types.
-        } else if (classOf[UDAF].isAssignableFrom(clazz)) {
-          udfExpr = Some(HiveUDAFFunction(
-            name,
-            new HiveFunctionWrapper(clazz.getName),
-            input,
-            isUDAFBridgeRequired = true))
-          udfExpr.get.dataType // Force it to check input data types.
-        } else if (classOf[GenericUDTF].isAssignableFrom(clazz)) {
-          udfExpr = Some(HiveGenericUDTF(name, new HiveFunctionWrapper(clazz.getName), input))
-          udfExpr.get.asInstanceOf[HiveGenericUDTF].elementSchema // Force it to check data types.
+    // Current thread context classloader may not be the one loaded the class. Need to switch
+    // context classloader to initialize instance properly.
+    Utils.withContextClassLoader(clazz.getClassLoader) {
+      Try(super.makeFunctionExpression(name, clazz, input)).getOrElse {
+        var udfExpr: Option[Expression] = None
+        try {
+          // When we instantiate hive UDF wrapper class, we may throw exception if the input
+          // expressions don't satisfy the hive UDF, such as type mismatch, input number
+          // mismatch, etc. Here we catch the exception and throw AnalysisException instead.
+          if (classOf[UDF].isAssignableFrom(clazz)) {
+            udfExpr = Some(HiveSimpleUDF(name, new HiveFunctionWrapper(clazz.getName), input))
+            udfExpr.get.dataType // Force it to check input data types.
+          } else if (classOf[GenericUDF].isAssignableFrom(clazz)) {
+            udfExpr = Some(HiveGenericUDF(name, new HiveFunctionWrapper(clazz.getName), input))
+            udfExpr.get.dataType // Force it to check input data types.
+          } else if (classOf[AbstractGenericUDAFResolver].isAssignableFrom(clazz)) {
+            udfExpr = Some(HiveUDAFFunction(name, new HiveFunctionWrapper(clazz.getName), input))
+            udfExpr.get.dataType // Force it to check input data types.
+          } else if (classOf[UDAF].isAssignableFrom(clazz)) {
+            udfExpr = Some(HiveUDAFFunction(
+              name,
+              new HiveFunctionWrapper(clazz.getName),
+              input,
+              isUDAFBridgeRequired = true))
+            udfExpr.get.dataType // Force it to check input data types.
+          } else if (classOf[GenericUDTF].isAssignableFrom(clazz)) {
+            udfExpr = Some(HiveGenericUDTF(name, new HiveFunctionWrapper(clazz.getName), input))
+            udfExpr.get.asInstanceOf[HiveGenericUDTF].elementSchema // Force it to check data types.
+          }
+        } catch {
+          case NonFatal(e) =>
+            val noHandlerMsg = s"No handler for UDF/UDAF/UDTF '${clazz.getCanonicalName}': $e"
+            val errorMsg =
+              if (classOf[GenericUDTF].isAssignableFrom(clazz)) {
+                s"$noHandlerMsg\nPlease make sure your function overrides " +
+                  "`public StructObjectInspector initialize(ObjectInspector[] args)`."
+              } else {
+                noHandlerMsg
+              }
+            val analysisException = new AnalysisException(errorMsg)
+            analysisException.setStackTrace(e.getStackTrace)
+            throw analysisException
+        }
+        udfExpr.getOrElse {
+          throw new AnalysisException(s"No handler for UDF/UDAF/UDTF '${clazz.getCanonicalName}'")
         }
-      } catch {
-        case NonFatal(e) =>
-          val noHandlerMsg = s"No handler for UDF/UDAF/UDTF '${clazz.getCanonicalName}': $e"
-          val errorMsg =
-            if (classOf[GenericUDTF].isAssignableFrom(clazz)) {
-              s"$noHandlerMsg\nPlease make sure your function overrides " +
-                "`public StructObjectInspector initialize(ObjectInspector[] args)`."
-            } else {
-              noHandlerMsg
-            }
-          val analysisException = new AnalysisException(errorMsg)
-          analysisException.setStackTrace(e.getStackTrace)
-          throw analysisException
-      }
-      udfExpr.getOrElse {
-        throw new AnalysisException(s"No handler for UDF/UDAF/UDTF '${clazz.getCanonicalName}'")
       }
     }
   }
diff --git a/sql/hive/src/test/noclasspath/README b/sql/hive/src/test/noclasspath/README
new file mode 100644
index 0000000000000..8ce1b0bd09668
--- /dev/null
+++ b/sql/hive/src/test/noclasspath/README
@@ -0,0 +1 @@
+Place files which are being used as resources of tests but shouldn't be added to classpath.
\ No newline at end of file
diff --git a/sql/hive/src/test/noclasspath/TestUDTF-spark-26560.jar b/sql/hive/src/test/noclasspath/TestUDTF-spark-26560.jar
new file mode 100644
index 0000000000000..b73b17d5c7880
Binary files /dev/null and b/sql/hive/src/test/noclasspath/TestUDTF-spark-26560.jar differ
diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/SQLQuerySuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/SQLQuerySuite.scala
index 2fcc8229a9f57..9f57776233e2f 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/SQLQuerySuite.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/SQLQuerySuite.scala
@@ -42,6 +42,7 @@ import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.test.SQLTestUtils
 import org.apache.spark.sql.types._
 import org.apache.spark.unsafe.types.CalendarInterval
+import org.apache.spark.util.Utils
 
 case class Nested1(f1: Nested2)
 case class Nested2(f2: Nested3)
@@ -2327,4 +2328,51 @@ class SQLQuerySuite extends QueryTest with SQLTestUtils with TestHiveSingleton {
       }
     }
   }
+
+  test("SPARK-26560 Spark should be able to run Hive UDF using jar regardless of " +
+    "current thread context classloader") {
+    // force to use Spark classloader as other test (even in other test suites) may change the
+    // current thread's context classloader to jar classloader
+    Utils.withContextClassLoader(Utils.getSparkClassLoader) {
+      withUserDefinedFunction("udtf_count3" -> false) {
+        val sparkClassLoader = Thread.currentThread().getContextClassLoader
+
+        // This jar file should not be placed to the classpath; GenericUDTFCount3 is slightly
+        // modified version of GenericUDTFCount2 in hive/contrib, which emits the count for
+        // three times.
+        val jarPath = "src/test/noclasspath/TestUDTF-spark-26560.jar"
+        val jarURL = s"file://${System.getProperty("user.dir")}/$jarPath"
+
+        sql(
+          s"""
+             |CREATE FUNCTION udtf_count3
+             |AS 'org.apache.hadoop.hive.contrib.udtf.example.GenericUDTFCount3'
+             |USING JAR '$jarURL'
+          """.stripMargin)
+
+        assert(Thread.currentThread().getContextClassLoader eq sparkClassLoader)
+
+        // JAR will be loaded at first usage, and it will change the current thread's
+        // context classloader to jar classloader in sharedState.
+        // See SessionState.addJar for details.
+        checkAnswer(
+          sql("SELECT udtf_count3(a) FROM (SELECT 1 AS a FROM src LIMIT 3) t"),
+          Row(3) :: Row(3) :: Row(3) :: Nil)
+
+        assert(Thread.currentThread().getContextClassLoader ne sparkClassLoader)
+        assert(Thread.currentThread().getContextClassLoader eq
+          spark.sqlContext.sharedState.jarClassLoader)
+
+        // Roll back to the original classloader and run query again. Without this line, the test
+        // would pass, as thread's context classloader is changed to jar classloader. But thread
+        // context classloader can be changed from others as well which would fail the query; one
+        // example is spark-shell, which thread context classloader rolls back automatically. This
+        // mimics the behavior of spark-shell.
+        Thread.currentThread().setContextClassLoader(sparkClassLoader)
+        checkAnswer(
+          sql("SELECT udtf_count3(a) FROM (SELECT 1 AS a FROM src LIMIT 3) t"),
+          Row(3) :: Row(3) :: Row(3) :: Nil)
+      }
+    }
+  }
 }