World 9

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


 * World 9 (Super Mario Bros.) - World 9, a glitched world of Super Mario Bros..
 * World 9 (Super Mario Bros.: The Lost Levels) - World 9 of Super Mario Bros.: The Lost Levels.
 * Warp Zone - World 9 and the final world of Super Mario Bros. 3.
 * Tower - World 9 and the final world of Donkey Kong on Game Boy.
 * World 9 (New Super Mario Bros. Wii) - World 9 and the special world of New Super Mario Bros. Wii.
 * Golden Temple - World 9 and the final world of Donkey Kong Country Returns.
 * Special 1 - World 9 of Super Mario 3D Land.
 * World Star - World 9 of New Super Mario Bros. 2.
 * Cloud - World 9 and the final world of Donkey Kong Country Returns 3D.
 * Superstar Road - World 9 and the final world of New Super Mario Bros. U and New Super Luigi U.
 * World Star - World 9 of Super Mario 3D World.
 * World 9 (Dr. Mario World) - World 9 of Dr. Mario World.