Hollywood Squares (originally The Hollywood Squares) is an American game show in which two contestants compete in a game of tic-tac-toe to win cash and prizes. The show piloted on NBC in 1965 and the regular series debuted in 1966 on the same network. The board for the game is a 3 × 3 vertical stack of open-faced cubes, each occupied by a celebrity seated at a desk and facing the contestants. The stars are asked questions by the host and the contestants judge the truth of their answers to gain squares in the right pattern to win the game.

Though Hollywood Squares was a legitimate game show, the game largely acted as the background for the show's comedy in the form of joke answers (commonly called "zingers" by the production staff), often given by the stars prior to their real answer. The show's writers usually supplied the jokes. In addition, the stars were given the questions' subjects and bluff (plausible, but incorrect) answers prior to the show. The show was scripted in this sense, but the gameplay was not. In any case, as original host Peter Marshall explained at the beginning of the Secret Square game, the celebrities were briefed prior to the show to help them with bluff answers, but they heard the actual questions for the first time as they were asked on air.

Marshall hosted the original version of Hollywood Squares that aired on NBC from 1966 to 1980, as well as a nighttime syndicated version that ran from 1971 to 1981. It then returned to NBC in 1983 as part of a 60-minute hybrid series with Match Game, featuring Jon Bauman hosting the Hollywood Squares portion of that show. Following Marshall's retirement, the show has since been revived twice in syndication: a version hosted by John Davidson from 1986 to 1989, and another hosted by Tom Bergeron from 1998 to 2004.

In 2013, TV Guide ranked it at No. 7 in its list of the 60 greatest game shows ever. Internationally, there have been multiple versions produced under a variety of names (see International versions below).