diff --git a/core/src/main/java/org/opensearch/sql/calcite/utils/BuiltinFunctionUtils.java b/core/src/main/java/org/opensearch/sql/calcite/utils/BuiltinFunctionUtils.java
index c668cad420..71d224f626 100644
--- a/core/src/main/java/org/opensearch/sql/calcite/utils/BuiltinFunctionUtils.java
+++ b/core/src/main/java/org/opensearch/sql/calcite/utils/BuiltinFunctionUtils.java
@@ -15,6 +15,7 @@
 import org.apache.calcite.sql.SqlOperator;
 import org.apache.calcite.sql.fun.SqlLibraryOperators;
 import org.apache.calcite.sql.fun.SqlStdOperatorTable;
+import org.apache.calcite.sql.fun.SqlTrimFunction;
 import org.apache.calcite.sql.type.ReturnTypes;
 import org.opensearch.sql.calcite.CalcitePlanContext;
 import org.opensearch.sql.calcite.udf.mathUDF.SqrtFunction;
@@ -53,10 +54,28 @@ static SqlOperator translate(String op) {
       case "/":
         return SqlStdOperatorTable.DIVIDE;
         // Built-in String Functions
+      case "CONCAT":
+        return SqlLibraryOperators.CONCAT_FUNCTION;
+      case "CONCAT_WS":
+        return SqlLibraryOperators.CONCAT_WS;
+      case "LIKE":
+        return SqlLibraryOperators.ILIKE;
+      case "LTRIM", "RTRIM", "TRIM":
+        return SqlStdOperatorTable.TRIM;
+      case "LENGTH":
+        return SqlStdOperatorTable.CHAR_LENGTH;
       case "LOWER":
         return SqlStdOperatorTable.LOWER;
-      case "LIKE":
-        return SqlStdOperatorTable.LIKE;
+      case "POSITION":
+        return SqlStdOperatorTable.POSITION;
+      case "REVERSE":
+        return SqlLibraryOperators.REVERSE;
+      case "RIGHT":
+        return SqlLibraryOperators.RIGHT;
+      case "SUBSTRING":
+        return SqlStdOperatorTable.SUBSTRING;
+      case "UPPER":
+        return SqlStdOperatorTable.UPPER;
         // Built-in Math Functions
       case "ABS":
         return SqlStdOperatorTable.ABS;
@@ -99,6 +118,30 @@ static SqlOperator translate(String op) {
   static List<RexNode> translateArgument(
       String op, List<RexNode> argList, CalcitePlanContext context) {
     switch (op.toUpperCase(Locale.ROOT)) {
+      case "TRIM":
+        List<RexNode> trimArgs =
+            new ArrayList<>(
+                List.of(
+                    context.rexBuilder.makeFlag(SqlTrimFunction.Flag.BOTH),
+                    context.rexBuilder.makeLiteral(" ")));
+        trimArgs.addAll(argList);
+        return trimArgs;
+      case "LTRIM":
+        List<RexNode> LTrimArgs =
+            new ArrayList<>(
+                List.of(
+                    context.rexBuilder.makeFlag(SqlTrimFunction.Flag.LEADING),
+                    context.rexBuilder.makeLiteral(" ")));
+        LTrimArgs.addAll(argList);
+        return LTrimArgs;
+      case "RTRIM":
+        List<RexNode> RTrimArgs =
+            new ArrayList<>(
+                List.of(
+                    context.rexBuilder.makeFlag(SqlTrimFunction.Flag.TRAILING),
+                    context.rexBuilder.makeLiteral(" ")));
+        RTrimArgs.addAll(argList);
+        return RTrimArgs;
       case "ATAN":
         List<RexNode> AtanArgs = new ArrayList<>(argList);
         if (AtanArgs.size() == 1) {
diff --git a/integ-test/src/test/java/org/opensearch/sql/calcite/standalone/CalcitePPLBuiltinFunctionIT.java b/integ-test/src/test/java/org/opensearch/sql/calcite/standalone/CalcitePPLBuiltinFunctionIT.java
index 112d6d4ff9..2ed726fb4b 100644
--- a/integ-test/src/test/java/org/opensearch/sql/calcite/standalone/CalcitePPLBuiltinFunctionIT.java
+++ b/integ-test/src/test/java/org/opensearch/sql/calcite/standalone/CalcitePPLBuiltinFunctionIT.java
@@ -11,6 +11,7 @@
 import java.io.IOException;
 import org.json.JSONObject;
 import org.junit.jupiter.api.Test;
+import org.opensearch.client.Request;
 
 public class CalcitePPLBuiltinFunctionIT extends CalcitePPLIntegTestCase {
   @Override
@@ -31,4 +32,242 @@ public void testSqrtAndPow() {
 
     verifyDataRows(actual, rows("Hello", 30));
   }
+
+  // Test
+  @Test
+  public void testConcat() {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where name=concat('He', 'llo') | fields name, age",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("Hello", 30));
+  }
+
+  @Test
+  public void testConcatWithField() throws IOException {
+    Request request1 =
+        new Request("PUT", "/opensearch-sql_test_index_state_country/_doc/5?refresh=true");
+    request1.setJsonEntity(
+        "{\"name\":\"HelloWay\",\"age\":27,\"state\":\"Way\",\"country\":\"Canada\",\"year\":2023,\"month\":4}");
+    client().performRequest(request1);
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where name=concat('Hello', state) | fields name, age",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("HelloWay", 27));
+  }
+
+  @Test
+  public void testConcatWs() throws IOException {
+    Request request1 =
+        new Request("PUT", "/opensearch-sql_test_index_state_country/_doc/5?refresh=true");
+    request1.setJsonEntity(
+        "{\"name\":\"John,Way\",\"age\":27,\"state\":\"Way\",\"country\":\"Canada\",\"year\":2023,\"month\":4}");
+    client().performRequest(request1);
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where name=concat_ws(',', 'John', state) | fields name, age",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("John,Way", 27));
+  }
+
+  @Test
+  public void testLength() {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where length(name) = 5 | fields name, age", TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("Hello", 30));
+  }
+
+  @Test
+  public void testLengthShouldBeInsensitive() {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where leNgTh(name) = 5 | fields name, age", TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("Hello", 30));
+  }
+
+  @Test
+  public void testLower() {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where lower(name) = 'hello' | fields name, age",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("Hello", 30));
+  }
+
+  @Test
+  public void testUpper() {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where upper(name) = upper('hello') | fields name, age",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("Hello", 30));
+  }
+
+  @Test
+  public void testLike() {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where like(name, '_ello%%') | fields name, age",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("Hello", 30));
+  }
+
+  @Test
+  public void testSubstring() {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where substring(name, 2, 2) = 'el' | fields name, age",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("Hello", 30));
+  }
+
+  @Test
+  public void testPosition() {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where position('He' in name) = 1 | fields name, age",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("Hello", 30));
+  }
+
+  @Test
+  public void testTrim() throws IOException {
+    prepareTrim();
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where Trim(name) = 'Jim' | fields name, age",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("   Jim", 27), rows("Jim   ", 57), rows("   Jim   ", 70));
+  }
+
+  @Test
+  public void testRTrim() throws IOException {
+    prepareTrim();
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where RTrim(name) = 'Jim' | fields name, age",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("Jim   ", 57));
+  }
+
+  @Test
+  public void testLTrim() throws IOException {
+    prepareTrim();
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where LTrim(name) = 'Jim' | fields name, age",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("   Jim", 27));
+  }
+
+  @Test
+  public void testReverse() throws IOException {
+    Request request1 =
+        new Request("PUT", "/opensearch-sql_test_index_state_country/_doc/5?refresh=true");
+    request1.setJsonEntity(
+        "{\"name\":\"DeD\",\"age\":27,\"state\":\"B.C\",\"country\":\"Canada\",\"year\":2023,\"month\":4}");
+    client().performRequest(request1);
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where Reverse(name) = name | fields name, age",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("DeD", 27));
+  }
+
+  @Test
+  public void testRight() throws IOException {
+    Request request1 =
+        new Request("PUT", "/opensearch-sql_test_index_state_country/_doc/5?refresh=true");
+    request1.setJsonEntity(
+        "{\"name\":\"DeD\",\"age\":27,\"state\":\"B.C\",\"country\":\"Canada\",\"year\":2023,\"month\":4}");
+    client().performRequest(request1);
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where right(name, 2) = 'lo' | fields name, age",
+                TEST_INDEX_STATE_COUNTRY));
+
+    verifySchema(actual, schema("name", "string"), schema("age", "integer"));
+
+    verifyDataRows(actual, rows("Hello", 30));
+  }
+
+  private void prepareTrim() throws IOException {
+    Request request1 =
+        new Request("PUT", "/opensearch-sql_test_index_state_country/_doc/5?refresh=true");
+    request1.setJsonEntity(
+        "{\"name\":\"  "
+            + " Jim\",\"age\":27,\"state\":\"B.C\",\"country\":\"Canada\",\"year\":2023,\"month\":4}");
+    client().performRequest(request1);
+    Request request2 =
+        new Request("PUT", "/opensearch-sql_test_index_state_country/_doc/6?refresh=true");
+    request2.setJsonEntity(
+        "{\"name\":\"Jim  "
+            + " \",\"age\":57,\"state\":\"B.C\",\"country\":\"Canada\",\"year\":2023,\"month\":4}");
+    client().performRequest(request2);
+    Request request3 =
+        new Request("PUT", "/opensearch-sql_test_index_state_country/_doc/7?refresh=true");
+    request3.setJsonEntity(
+        "{\"name\":\"   Jim  "
+            + " \",\"age\":70,\"state\":\"B.C\",\"country\":\"Canada\",\"year\":2023,\"month\":4}");
+    client().performRequest(request3);
+  }
 }