World 9

World 9 (also written as World Nine) can refer to:


 * World 9 (Super Mario Bros.: The Lost Levels) - World 9 of Super Mario Bros.: The Lost Levels.
 * Warp Zone - World 9 of Super Mario Bros. 3.
 * World 9 (New Super Mario Bros. Wii) - World 9 of New Super Mario Bros. Wii.