New Super Mario Bros.^[a] is a 2006 platform game developed and published by Nintendo for the Nintendo DS. It was first released in May 2006 in North America and Japan, and in PAL regions in June 2006. It is the first installment in the New Super Mario Bros. subseries of the Super Mario franchise, and follows Mario as he fights his way through Bowser's henchmen to rescue Princess Peach. Mario has access to several old and new power-ups that help him complete his quest, including the Super Mushroom, the Fire Flower, and the Super Star, each giving him unique abilities. While traveling through eight worlds with more than 80 levels, Mario must defeat Bowser Jr. and Bowser before saving Princess Peach.

New Super Mario Bros. was commercially and critically successful; praise went towards the game's improvements and introductions made to the Mario franchise and faithfulness to older Mario games, while criticism was targeted at its low difficulty level and lingering similarities to previous games. It was called one of the best games available for the Nintendo DS by several critics with some further calling it one of the best side-scrolling Super Mario titles. It sold over 30 million copies worldwide, making it the best-selling game for the Nintendo DS and one of the best-selling video games of all time. The game's success led to a line of sequels released for the Wii, Nintendo 3DS, Wii U, and Nintendo Switch.