Moussaka (, UK also , US also ) is an eggplant- or potato-based dish, often including ground meat, which is common in the Balkans and the Middle East, with many local and regional variations.

The best-known version in Europe and the Americas is the Greek variant created in the 1920s by Nikolaos Tselementes. Many versions have a top layer made of milk-based sauce thickened with egg (custard) or flour (béchamel sauce). In Greece, the dish is layered and typically served hot. Tselementes also proposed a vegan variant for orthodox fast days. Romania also has a vegan version that replaces meat with mushrooms or a mix of sautéed onions and rice.

The versions in Egypt, Turkey and the rest of the Middle East are quite different. In Egypt, messa'aa can be made vegan or vegetarian as well as with meat; in all cases, the main ingredient is the fried eggplant. In Turkey, mussaka consists of thinly sliced and fried eggplant served in a tomato-based meat sauce, warm or at room temperature. In Saudi Arabia muṣagga‘a is eaten hot, but in other Arab countries, it is often eaten cold, but occasionally hot as well.