Tab (stylized as TaB) was a diet cola soft drink created and produced by The Coca-Cola Company, introduced in 1963 and discontinued in 2020. Coca-Cola's first diet drink, Tab was popular among some people throughout the 1960s and 1970s, as an alternative to Coca-Cola Classic. Several variations were made, including a number of fruit-flavored, root beer, and ginger ale versions. Caffeine-free and clear variations were released in the late 1980s and early 1990s.

Following studies in the early 1970s that linked saccharin, Tab's main sweetener, with bladder cancer in rats, the United States Congress mandated warning labels on products containing the sweetener. The label requirement was later repealed when no plausibility was found for saccharin causing cancer in humans.

Tab's popularity declined after the Coca-Cola company's introduction of Diet Coke in 1982, though it remained the best-selling diet soda of that year. Coca-Cola continued to produce Tab in the United States, though in considerably smaller quantities than its more popular mainstay beverages, such as Coca-Cola and Diet Coke. According to the company, three million cases of Tab were made in 2011, and the beverage retained a cult following. In 2006, a Tab-branded energy drink was released, though it used a different formula from the standard cola. Coca-Cola discontinued Tab at the end of 2020.