diff --git a/mlir/lib/Bindings/Python/IRAttributes.cpp b/mlir/lib/Bindings/Python/IRAttributes.cpp
--- a/mlir/lib/Bindings/Python/IRAttributes.cpp
+++ b/mlir/lib/Bindings/Python/IRAttributes.cpp
@@ -698,7 +698,13 @@
 
   intptr_t dunderLen() { return mlirDictionaryAttrGetNumElements(*this); }
 
+  bool dunderContains(const std::string &name) {
+    return !mlirAttributeIsNull(
+        mlirDictionaryAttrGetElementByName(*this, toMlirStringRef(name)));
+  }
+
   static void bindDerived(ClassTy &c) {
+    c.def("__contains__", &PyDictAttribute::dunderContains);
     c.def("__len__", &PyDictAttribute::dunderLen);
     c.def_static(
         "get",
diff --git a/mlir/test/python/ir/attributes.py b/mlir/test/python/ir/attributes.py
--- a/mlir/test/python/ir/attributes.py
+++ b/mlir/test/python/ir/attributes.py
@@ -340,6 +340,12 @@
     # CHECK: "string"
     print(a['stringattr'])
 
+    # CHECK: True
+    print('stringattr' in a)
+
+    # CHECK: False
+    print('not_in_dict' in a)
+
     # Check that exceptions are raised as expected.
     try:
       _ = a['does_not_exist']