The nickname for Thanksgiving that comes from turkey being the meal's central dish is “Turkey Day.”
Roast turkey became the defining centerpiece of the modern Thanksgiving dinner, making the bird a natural shorthand for the holiday itself. The expression is informal and usually appears in casual speech, advertising, headlines, and humorous references rather than in formal names for the holiday.
Turkey was not necessarily the centerpiece of every early thanksgiving celebration. The familiar national Thanksgiving tradition developed especially strongly during the 19th century, when writers and public figures promoted a shared American holiday. By 1857, turkey had become part of the traditional Thanksgiving dinner in New England, and its prominence continued to grow.
The meal also includes foods such as stuffing, mashed potatoes, gravy, cranberry sauce, squash, and green beans, but those dishes did not produce the holiday's best-known nickname. Regional and family menus vary widely, and some households serve ham, goose, seafood, or a plant-based substitute. Even so, “Turkey Day” remains recognizable because turkey is still the conventional main dish associated with Thanksgiving.