A hotdish or hot dish is a casserole dish that typically contains a starch, a meat, and a canned or frozen vegetable mixed with canned soup. The dish originates in the Upper Midwest region of the United States, where it remains popular, particularly in Minnesota, South Dakota, Wisconsin, North Dakota, and eastern Montana. Hotdish is cooked in a single baking dish, and served hot. It commonly appears at communal gatherings such as family reunions, potlucks, and church suppers. A classic example known as "tater tot hotdish" is made with ground beef, topped with tater tots, and flavored with thick, condensed cream of mushroom soup sauce.

A casserole is a kind of large, deep pan or bowl used for cooking a variety of dishes in the oven; it is also a category of foods cooked in such a vessel. To distinguish the two uses, the pan can be called a "casserole dish" or "casserole pan", whereas the food is simply "a casserole". The same pan is often used both for cooking and for serving.