diff --git a/core/src/main/java/org/opensearch/sql/planner/physical/ProjectOperator.java b/core/src/main/java/org/opensearch/sql/planner/physical/ProjectOperator.java
index 496e4e6ddb..adc05108eb 100644
--- a/core/src/main/java/org/opensearch/sql/planner/physical/ProjectOperator.java
+++ b/core/src/main/java/org/opensearch/sql/planner/physical/ProjectOperator.java
@@ -9,8 +9,10 @@
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableMap.Builder;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Optional;
+import java.util.Set;
 import java.util.stream.Collectors;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -52,10 +54,23 @@ public boolean hasNext() {
     return input.hasNext();
   }
 
+  private String handleDuplicateColumns(String newName, Set takenNames) {
+    if (takenNames.contains(newName)) {
+      int appendedNum = 1;
+      while (takenNames.contains(String.format("%s%d", newName, appendedNum))) {
+        appendedNum++;
+      }
+      newName = String.format("%s%d", newName, appendedNum);
+    }
+    takenNames.add(newName);
+    return newName;
+  }
+
   @Override
   public ExprValue next() {
     ExprValue inputValue = input.next();
     ImmutableMap.Builder<String, ExprValue> mapBuilder = new Builder<>();
+    Set<String> columns = new HashSet<>();
 
     // ParseExpression will always override NamedExpression when identifier conflicts
     // TODO needs a better implementation, see https://github.com/opensearch-project/sql/issues/458
@@ -64,25 +79,27 @@ public ExprValue next() {
       Optional<NamedExpression> optionalParseExpression = namedParseExpressions.stream()
           .filter(parseExpr -> parseExpr.getNameOrAlias().equals(expr.getNameOrAlias()))
           .findFirst();
+
       if (optionalParseExpression.isEmpty()) {
-        mapBuilder.put(expr.getNameOrAlias(), exprValue);
+        mapBuilder.put(handleDuplicateColumns(expr.getNameOrAlias(), columns), exprValue);
         continue;
       }
 
       NamedExpression parseExpression = optionalParseExpression.get();
       ExprValue sourceFieldValue = inputValue.bindingTuples()
           .resolve(((ParseExpression) parseExpression.getDelegated()).getSourceField());
+      String columnName = handleDuplicateColumns(parseExpression.getNameOrAlias(), columns);
       if (sourceFieldValue.isMissing()) {
         // source field will be missing after stats command, read from inputValue if it exists
         // otherwise do nothing since it should not appear as a field
         ExprValue tupleValue =
-            ExprValueUtils.getTupleValue(inputValue).get(parseExpression.getNameOrAlias());
+            ExprValueUtils.getTupleValue(inputValue).get(columnName);
         if (tupleValue != null) {
-          mapBuilder.put(parseExpression.getNameOrAlias(), tupleValue);
+          mapBuilder.put(columnName, tupleValue);
         }
       } else {
         ExprValue parsedValue = parseExpression.valueOf(inputValue.bindingTuples());
-        mapBuilder.put(parseExpression.getNameOrAlias(), parsedValue);
+        mapBuilder.put(columnName, parsedValue);
       }
     }
     return ExprTupleValue.fromExprValueMap(mapBuilder.build());