diff --git a/backends-velox/src/main/scala/org/apache/gluten/execution/ColumnarPartialProjectExec.scala b/backends-velox/src/main/scala/org/apache/gluten/execution/ColumnarPartialProjectExec.scala
index d657c3e3031..71936379286 100644
--- a/backends-velox/src/main/scala/org/apache/gluten/execution/ColumnarPartialProjectExec.scala
+++ b/backends-velox/src/main/scala/org/apache/gluten/execution/ColumnarPartialProjectExec.scala
@@ -297,6 +297,22 @@ object ColumnarPartialProjectExec {
     HiveUDFTransformer.isHiveUDF(h) && !VeloxHiveUDFTransformer.isSupportedHiveUDF(h)
   }
 
+  /**
+   * Returns true for generic catalyst expressions that Velox cannot offload and should be pulled
+   * into ColumnarPartialProject, excluding ScalaUDF/HiveUDF and non-row-evaluable wrappers.
+   */
+  private def isUnmappedGlutenExpr(expr: Expression): Boolean = expr match {
+    case _: ScalaUDF => false
+    case _ if HiveUDFTransformer.isHiveUDF(expr) => false
+    case _: Literal | _: AttributeReference | _: BoundReference => false
+    case _: NamedExpression => false
+    case _ =>
+      expr.deterministic &&
+      !expr.isInstanceOf[Unevaluable] &&
+      !expr.isInstanceOf[LambdaFunction] &&
+      !ExpressionMappings.expressionsMap.contains(expr.getClass)
+  }
+
   private def isBlacklistExpression(e: Expression): Boolean = {
     ExpressionMappings.blacklistExpressionMap.contains(e.getClass)
   }
@@ -307,6 +323,7 @@ object ColumnarPartialProjectExec {
       case _: ScalaUDF => true
       case h if containsUnsupportedHiveUDF(h) => true
       case e if isBlacklistExpression(e) => true
+      case e if isUnmappedGlutenExpr(e) => true
       case p => p.children.exists(c => containsUDFOrBlacklistExpression(c))
     }
   }
@@ -339,6 +356,8 @@ object ColumnarPartialProjectExec {
         replaceByAlias(h, replacedAlias)
       case e if isBlacklistExpression(e) =>
         replaceByAlias(e, replacedAlias)
+      case e if isUnmappedGlutenExpr(e) =>
+        replaceByAlias(e, replacedAlias)
       case au @ Alias(_: ScalaUDF, _) =>
         val replaceIndex = replacedAlias.indexWhere(r => r.exprId == au.exprId)
         if (replaceIndex == -1) {
diff --git a/backends-velox/src/test/scala/org/apache/gluten/expression/UDFPartialProjectSuite.scala b/backends-velox/src/test/scala/org/apache/gluten/expression/UDFPartialProjectSuite.scala
index 41cd9ac186a..1ccf0b3fdf8 100644
--- a/backends-velox/src/test/scala/org/apache/gluten/expression/UDFPartialProjectSuite.scala
+++ b/backends-velox/src/test/scala/org/apache/gluten/expression/UDFPartialProjectSuite.scala
@@ -20,9 +20,13 @@ import org.apache.gluten.config.GlutenConfig
 import org.apache.gluten.execution.{ColumnarPartialProjectExec, WholeStageTransformerSuite}
 
 import org.apache.spark.SparkConf
+import org.apache.spark.sql.catalyst.FunctionIdentifier
+import org.apache.spark.sql.catalyst.expressions.{Expression, ExpressionInfo, UnaryExpression}
+import org.apache.spark.sql.catalyst.expressions.codegen.CodegenFallback
 import org.apache.spark.sql.catalyst.optimizer.{ConstantFolding, NullPropagation}
 import org.apache.spark.sql.execution.ProjectExec
 import org.apache.spark.sql.functions.udf
+import org.apache.spark.sql.types.{BooleanType, DataType}
 
 import java.io.File
 
@@ -30,6 +34,17 @@ case class MyStruct(a: Long, b: Array[Long])
 
 case class MyStructWithNullValue(a: Option[Long], b: Array[Long])
 
+case class DummyUnmappedExpr(child: Expression) extends UnaryExpression with CodegenFallback {
+  override def dataType: DataType = BooleanType
+
+  override protected def nullSafeEval(input: Any): Any = {
+    input.asInstanceOf[Long] % 2 == 0
+  }
+
+  override protected def withNewChildInternal(newChild: Expression): DummyUnmappedExpr =
+    copy(child = newChild)
+}
+
 class UDFPartialProjectSuite extends WholeStageTransformerSuite {
   disableFallbackCheck
   override protected val resourcePath: String = "/tpch-data-parquet"
@@ -64,9 +79,22 @@ class UDFPartialProjectSuite extends WholeStageTransformerSuite {
     spark.udf.register("no_argument", noArgument)
     val concat = udf((x: String) => x + "_concat")
     spark.udf.register("concat_concat", concat)
+    spark.sessionState.functionRegistry.registerFunction(
+      FunctionIdentifier("dummy_unmapped"),
+      new ExpressionInfo(classOf[DummyUnmappedExpr].getName, "dummy_unmapped"),
+      (children: Seq[Expression]) => DummyUnmappedExpr(children.head)
+    )
 
   }
 
+  test("fallback generic unmapped expression via partial project") {
+    runQueryAndCompare(
+      "SELECT sum(cast(dummy_unmapped(cast(l_orderkey as long)) as int)" +
+        " + hash(l_partkey)) from lineitem") {
+      checkGlutenPlan[ColumnarPartialProjectExec]
+    }
+  }
+
   ignore("test plus_one") {
     runQueryAndCompare("SELECT sum(plus_one(cast(l_orderkey as long))) from lineitem") {
       checkGlutenPlan[ColumnarPartialProjectExec]