A tuna fish sandwich, also known as a tuna salad sandwich or a tuna sandwich, is a type of sandwich made from canned tuna, usually combined with other ingredients such as mayonnaise and celery. Other common variations include the tuna boat and tuna melt.The sandwich has been called "the mainstay of almost everyone's American childhood," and "the staple of the snatched office lunch for a generation." In the United States, 52% of canned tuna is used for sandwiches.