Super Smash Bros. is a series of platform fighting video games published by Nintendo. Created by Masahiro Sakurai, the Super Smash Bros. series is a crossover featuring many characters from other video game series created by Nintendo and other developers. Its gameplay is distinct from traditional fighting games, with players aiming to knock each other off of stages after accumulating damage with numerous attacks. The games have also featured a variety of side modes, including single-player story modes.

Sakurai conceived the idea of Super Smash Bros. while working at HAL Laboratory in 1998 with the help of Satoru Iwata. The series's first game, Super Smash Bros. (1999), was released for the Nintendo 64 and used characters from Nintendo franchises including Mario, Donkey Kong, The Legend of Zelda, Kirby, and Pokémon. The game was a success, and Sakurai was asked to make a sequel for the then-upcoming GameCube, Super Smash Bros. Melee, which was developed in 13 months and released in 2001.

After Sakurai left HAL Laboratory, Iwata, who had become Nintendo's president, convinced him to continue directing the series. Sakurai directed Super Smash Bros. Brawl (2008) for the Wii and Super Smash Bros. for Nintendo 3DS and Wii U (2014) for the Nintendo 3DS and Wii U. The series's most recent game, Super Smash Bros. Ultimate, was released in 2018 for the Nintendo Switch, with Sakurai again returning as director and Bandai Namco Studios aiding Sora Ltd., Sakurai's own company, in the game's development.

The Super Smash Bros. games have received critical acclaim and commercial success, with the series selling over 76 million units combined as of 2024 and multiple of its games being considered among the best of all time. The series has also attracted a dedicated community of competitive players who compete in esports tournaments, and Super Smash Bros. has inspired numerous other platform fighting games and has been credited for bringing popularity to several of the franchises whose characters it features.