A submarine sandwich (or just submarine where context would exclude the sea vessel, or even just sub) is any of various sandwiches made on a long roll split lengthwise, especially those including meat, cheese, lettuce, tomato, and various condiments. Because the meat is not fried, submarine sandwiches are generally considered to be healthier than hamburgers or hot dogs.

In regions of the United States there are many different terms for local variations on the idea:

Submarine sandwiches are sold by delicatessens and a number of fast-food restaurant chains, including Subway, Quizno's, Blimpie, and Schlotsky's.