diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/PartitioningUtils.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/PartitioningUtils.scala
index f7e225b0cdc96..5846d46e146ed 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/PartitioningUtils.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/PartitioningUtils.scala
@@ -545,6 +545,9 @@ object PartitioningUtils {
       partitionColumns: Seq[String],
       caseSensitive: Boolean): Unit = {
 
+    SchemaUtils.checkColumnNameDuplication(
+      partitionColumns, partitionColumns.mkString(", "), caseSensitive)
+
     partitionColumnsSchema(schema, partitionColumns, caseSensitive).foreach {
       field => field.dataType match {
         case _: AtomicType => // OK
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/sources/PartitionedWriteSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/sources/PartitionedWriteSuite.scala
index 1c4e2a967b0a2..6df1c5db14c26 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/sources/PartitionedWriteSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/sources/PartitionedWriteSuite.scala
@@ -24,7 +24,7 @@ import org.apache.hadoop.mapreduce.TaskAttemptContext
 
 import org.apache.spark.TestUtils
 import org.apache.spark.internal.Logging
-import org.apache.spark.sql.{QueryTest, Row}
+import org.apache.spark.sql.{AnalysisException, QueryTest, Row}
 import org.apache.spark.sql.catalyst.catalog.ExternalCatalogUtils
 import org.apache.spark.sql.catalyst.util.DateTimeUtils
 import org.apache.spark.sql.execution.datasources.SQLHadoopMapReduceCommitProtocol
@@ -156,4 +156,12 @@ class PartitionedWriteSuite extends QueryTest with SharedSparkSession {
       }
     }
   }
+
+  test("SPARK-31968: duplicate partition columns check") {
+    withTempPath { f =>
+      val e = intercept[AnalysisException](
+        Seq((3, 2)).toDF("a", "b").write.partitionBy("b", "b").csv(f.getAbsolutePath))
+      assert(e.getMessage.contains("Found duplicate column(s) b, b: `b`;"))
+    }
+  }
 }