Tetris (Russian: Тетрис), also known as a jigsaw puzzle, is an early video game designed and developed by Soviet computer scientist Alexey Pajitnov. The game was created on June 6, 1984, while he was working at the Dorodnicyn Computing Center of the USSR Academy of Sciences in Moscow. He took the name of the game from the Greek prefix "tetra-", which means "four" (each set of parts in the game, called Tetromino, has four parts) and tennis (tennis), the sport game Pajitnov most liked.

Games (or a variation thereof) are sold for virtually any video game console and computer operating system, as well as in graphical computers, mobile phones, portable music players, PDAs, and many other things. While many variants of Tetris were marketed in the 1980s, the Game Boy's handheld game, released in 1989, made the game one of the most popular. The 100th issue of Electronic Gaming Monthly magazine called Tetris "The Greatest Game of All Time". It has sold over 70 million copies.