Super Mario Bros. is a platform video game developed by Nintendo in late 1985 and published for the Nintendo Entertainment System as a sequel to the 1983 game Mario Bros. In Super Mario Bros., the titular character, Mario, seeks to rescue Princess Toadstool (later renamed Princess Peach) of the Mushroom Kingdom from Bowser, king of the Koopas. Mario's younger brother, Luigi, is playable by the second player in the game's multiplayer mode, and assumes the same plot role as Mario.

For over two decades, Super Mario Bros. was the best-selling video game of all time, before being outsold by Wii Sports in 2009. Excluding Game Boy Advance and Virtual Console sales, the game has sold 40.241 million copies worldwide. It was largely responsible for the initial success of the Nintendo Entertainment System, as well as ending the two-year slump of video game sales in the United States after the video game crash of 1983. As one of Shigeru Miyamoto's most influential early successes, it has inspired many clones, sequels, and spin-offs. Its theme music by Koji Kondo is recognized worldwide, even by those who have not played the game, and has been considered a representation for video game music in general.

The game was succeeded by two separate sequels that were produced for different markets: a Japanese sequel which features the same gameplay as the original and a Western sequel that was localized from an originally unrelated game titled Yume Kōjō: Doki Doki Panic. In both ...