What was the first Nintendo Switch game to sell more than 10 million copies?

Mario Kart 8 Deluxe was the first Nintendo Switch game to sell more than 10 million copies.

Mario Kart 8 Deluxe launched on April 28, 2017, as an enhanced version of Mario Kart 8, which originally appeared on Wii U. The Switch edition included the original game’s tracks and characters plus expanded battle modes, additional racers, and revised gameplay features.

Its strong sales were helped by the large installed base of the Switch, the series’ accessible multiplayer format, and its long commercial life. Unlike a brand-new numbered sequel, Deluxe adapted an existing game for Nintendo’s newer hybrid platform.

Sales milestones can vary depending on the reporting date and whether Nintendo counts units sold through particular reporting periods. Mario Kart 8 Deluxe ultimately became one of Nintendo’s best-selling games, but this answer refers to the early milestone identifying it as the first Switch title to pass 10 million copies.