A tuna salad sandwich contains a tuna salad mixture served between two slices of bread. The salad mixture itself usually contains pre-cooked, canned tuna, usually mixed with eggs and mayonnaise or a mayonnaise substitute such as mustard. Other variations include corn, tomatoes, celery, or other fruits or vegetables, depending on taste.
Tuna salad sandwiches are popular in the US where they are common at delis or sandwich shops. Additionally, "sandwiches" may be formed by simply serving the tuna salad with crackers.