Klax is a puzzle video game released in arcades in 1990 by Atari Games. It was designed by Dave Akers and Mark Stephen Pierce. The object is to catch colored blocks tumbling down a machine and arrange them in colored rows and patterns to make them disappear. Klax was originally published as a coin-op follow-up to Tetris, about which Atari Games were tangled in a legal dispute at the time.

The Atari 2600 port, released in the summer of 1990, was the last game for the system before the console was discontinued in early 1992. An unlicensed NES version was released by Tengen in 1990, although there's a licensed version released in Japan by Hudson Soft, who also brought you the Game Boy version.

The NES port was made by three people, David O'Riva, who was the programmer and did the music and sound for the game (O'Riva will soon quit Tengen to start Bitmasters after the game was released), Greg Williams for the graphics and Alex Rudis for music and sound.