diff --git a/pinot-query-planner/src/main/java/org/apache/pinot/query/planner/logical/RexExpressionUtils.java b/pinot-query-planner/src/main/java/org/apache/pinot/query/planner/logical/RexExpressionUtils.java
index 278e34ac0741..8bcf2bf6b634 100644
--- a/pinot-query-planner/src/main/java/org/apache/pinot/query/planner/logical/RexExpressionUtils.java
+++ b/pinot-query-planner/src/main/java/org/apache/pinot/query/planner/logical/RexExpressionUtils.java
@@ -34,6 +34,8 @@
 import org.apache.calcite.avatica.util.ByteString;
 import org.apache.calcite.rel.core.AggregateCall;
 import org.apache.calcite.rel.core.Window;
+import org.apache.calcite.rel.type.RelDataType;
+import org.apache.calcite.rel.type.RelDataTypeFactory;
 import org.apache.calcite.rex.RexBuilder;
 import org.apache.calcite.rex.RexCall;
 import org.apache.calcite.rex.RexInputRef;
@@ -106,6 +108,14 @@ private static RexNode toRexCall(RelBuilder builder, RexExpression.FunctionCall
       // Calcite creates IN as SEARCH
       return builder.in(operands.get(0), operands.subList(1, operands.size()));
     }
+    if (operator.kind == SqlKind.CAST) {
+      // The second operand only holds the target type name (see handleCast). Calcite would use its type as the result.
+      RexNode operand = operands.get(0);
+      RelDataTypeFactory typeFactory = builder.getTypeFactory();
+      RelDataType type = typeFactory.createTypeWithNullability(rexExpression.getDataType().toType(typeFactory),
+          operand.getType().isNullable());
+      return builder.getRexBuilder().makeCast(type, operand);
+    }
 
     return builder.call(operator, operands);
   }
diff --git a/pinot-query-planner/src/test/java/org/apache/pinot/query/planner/logical/RexExpressionUtilsTest.java b/pinot-query-planner/src/test/java/org/apache/pinot/query/planner/logical/RexExpressionUtilsTest.java
index 0d5355c36271..536b2ecb9483 100644
--- a/pinot-query-planner/src/test/java/org/apache/pinot/query/planner/logical/RexExpressionUtilsTest.java
+++ b/pinot-query-planner/src/test/java/org/apache/pinot/query/planner/logical/RexExpressionUtilsTest.java
@@ -28,6 +28,7 @@
 import org.apache.calcite.rex.RexCall;
 import org.apache.calcite.rex.RexInputRef;
 import org.apache.calcite.rex.RexLiteral;
+import org.apache.calcite.rex.RexNode;
 import org.apache.calcite.rex.RexUnknownAs;
 import org.apache.calcite.sql.SqlCollation;
 import org.apache.calcite.sql.SqlKind;
@@ -47,6 +48,7 @@
 
 import static org.testng.Assert.assertEquals;
 import static org.testng.Assert.assertSame;
+import static org.testng.Assert.assertTrue;
 
 
 /// Tests for RexExpressionUtils, focusing on the handleSearch method and null handling.
@@ -92,6 +94,18 @@ public void testSqlKindFunctionNames() {
     assertSame(RexExpressionUtils.getAggFunction(sum0), SqlStdOperatorTable.SUM0);
   }
 
+  @Test
+  public void testCastRoundTrip() {
+    // Plan nodes hold the target type of CAST as a STRING literal operand. Field "a" is a nullable INTEGER.
+    RelBuilder relBuilder =
+        RelBuilder.create(Frameworks.newConfigBuilder().build()).values(new String[]{"a"}, 1, null);
+    RexExpression castCall = new RexExpression.FunctionCall(ColumnDataType.DOUBLE, SqlKind.CAST.name(),
+        List.of(new RexExpression.InputRef(0), new RexExpression.Literal(ColumnDataType.STRING, "DOUBLE")));
+    RexNode rexNode = RexExpressionUtils.toRexNode(relBuilder, castCall);
+    assertTrue(rexNode.getType().isNullable());
+    assertEquals(RexExpressionUtils.fromRexNode(rexNode), castCall);
+  }
+
   @Test
   public void testHandleSearchNullLiteralInWithNullAsUnknown() {
     // Test: NULL IN (1, 2, 3) (when nullAs = UNKNOWN)