Chop suey is a dish, stir-fry is a type of dish. This is the biggest difference between these two foods. In fact, chop suey is a type of stir-fry. However, chop suey is a dish that is different to the quick, cheap and fast dish that you may find financially struggling students making from their dorms in college. When you think of a stir-fry you will often picture noodles, sauce, and vegetables, perhaps occasionally with meats and fried up and served as a delicious dish. However, chop suey is a type of stir-fry that does not always use noodles, actually, chop suey more often uses rice as the carbohydrate of the dish.
In contrast to chow mein, chop suey is often made with a thickened sauce, while chow mein uses a mix with soy sauce. Chow mein is often made with noodles, whereas chop suey is more often made with rice.