World 6-6

World 6-6 may refer to:
 * World 6-6 (Super Mario Bros. 3)
 * The Deep, Underground Maze, World 6-6 in Super Mario World 2: Yoshi's Island.
 * World 6-6 (New Super Mario Bros.)
 * World 6-6 (New Super Mario Bros. Wii)
 * Thrilling Spine Coaster, World 6-6 in New Super Mario Bros. U.
 * Spine Coaster Stowaways, World 6-6 in New Super Luigi U.
 * Bullet Bill Base, World 6-6 in Super Mario 3D World.