Development on Mario Kart World started as far back as when Mario Kart 8 Deluxe was just wrapping up production, and official work started at the end of 2017 as a title for the original Nintendo Switch. From the very beginning, the game started off as an open-world experience, which is why the game is called Mario Kart World instead of Mario Kart 9. Because of this, having 24 racers in a single game rather than 12, like in 8 Deluxe, was already in consideration.

Technical limitations of the original Nintendo Switch console made development very difficult, and the team shifted to the then-upcoming Nintendo Switch 2 in 2020. Because of the longer-than-anticipated development, the team released the Mario Kart 8 Deluxe Booster Course Pass to fill the void while Nintendo was still working on Mario Kart World.