diff --git a/mlir/include/mlir/IR/OpBase.td b/mlir/include/mlir/IR/OpBase.td
--- a/mlir/include/mlir/IR/OpBase.td
+++ b/mlir/include/mlir/IR/OpBase.td
@@ -845,6 +845,16 @@
   let constBuilderCall = "$_builder.getBoolAttr($0)";
 }
 
+// Index attribute.
+def IndexAttr :
+    TypedAttrBase<
+      Index, "IntegerAttr",
+      And<[CPred<"$_self.isa<IntegerAttr>()">,
+           CPred<"$_self.cast<IntegerAttr>().getType().isa<IndexType>()">]>,
+      "index attribute"> {
+  let returnType = [{ APInt }];
+}
+
 // Base class for any integer (regardless of signedness semantics) attributes
 // of fixed width.
 class AnyIntegerAttrBase<AnyI attrValType, string descr> :
diff --git a/mlir/test/IR/attribute.mlir b/mlir/test/IR/attribute.mlir
--- a/mlir/test/IR/attribute.mlir
+++ b/mlir/test/IR/attribute.mlir
@@ -8,6 +8,8 @@
   "test.int_attrs"() {
     // CHECK: any_i32_attr = 5 : ui32
     any_i32_attr = 5 : ui32,
+    // CHECK-SAME: index_attr = 8 : index
+    index_attr = 8 : index,
     // CHECK-SAME: si32_attr = 7 : si32
     si32_attr = 7 : si32,
     // CHECK-SAME: ui32_attr = 6 : ui32
diff --git a/mlir/test/lib/Dialect/Test/TestOps.td b/mlir/test/lib/Dialect/Test/TestOps.td
--- a/mlir/test/lib/Dialect/Test/TestOps.td
+++ b/mlir/test/lib/Dialect/Test/TestOps.td
@@ -199,6 +199,7 @@
 def IntAttrOp : TEST_Op<"int_attrs"> {
   let arguments = (ins
     AnyI32Attr:$any_i32_attr,
+    IndexAttr:$index_attr,
     UI32Attr:$ui32_attr,
     SI32Attr:$si32_attr
   );