"[2] The dish's popularity started to climb in the early twentieth century, but tuna sandwiches were already being served in nineteenth-century homes.

In 1893, Dell Montjoy Bradley, a New York socialite,[3] wrote a gourmet cookbook called Beverages and Sandwiches for Your Husband's Friends.

"[4][5] The sandwich is "emblematic of America’s working-class spirit" and its status "rests on three post–Industrial Revolution convenience foods: canned tuna, presliced wheat bread, and mayonnaise," according to James Beard Foundation Award winner Mari Uyehara.

[7] German immigrant Richard Hellmann began mass-producing mayonnaise, the other major ingredient of tuna salad, in New York City around 1905, for use by commercial food service businesses.

[13] Well-known 20th century American chefs including James Beard,[2] Julia Child,[14] Craig Claiborne[15] and comfort food cookbook author Sue Kreitzman[16] were advocates for the tuna sandwich.

American chef David Rosengarten is an advocate for a very simple style of finely chopped, easily spreadable tuna salad, almost like a fish pâté, reminiscent of New York City delicatessen food.

[18] A representative of the company which operates over 40,000 locations worldwide, denied the allegations, saying "These claims are meritless,” adding “Tuna is one of our most popular sandwiches.

"[18] The investigative TV show Inside Edition sent samples of Subway's tuna salad to Applied Food Technologies, a Florida company that carries out DNA testing of seafood.