| N/A | World 1 (New Super Mario Bros. Wii) | World 2 |
|---|
| World 1 (New Super Mario Bros. Wii) | |
 Half the map of World 1. | |
| Game(s) | New Super Mario Bros. Wii |
| # of levels | 9 |
World 1 is the first world in New Super Mario Bros. Wii, containing six levels, a fortress, a castle and a boss, three special stages - accessible by entering the Mushroom Houses - as well as housing Princess Peach's Castle. There are three special stages, two Red Toad Houses, and one Gold Toad House; the two Red Toad Houses occurring upon completion of World's 1-2 and 1-4, and the Gold Mushroom House occurring upon the completion of World 1-3.
Levels
Note: italics are secret exits.
| Level | Unlocks | Preview | Description |
|---|---|---|---|
| 1-1 | World 1-2 | 
| The first level of New Super Mario Bros. Wii. It introduces the Propeller Suit, Goombas and Koopa Troopas. This level is designed for new players. |
| 1-2 | World 1-3, Red Mushroom House | 
| This is the first underground level. |
| 1-3 | World 1-Fortress, Gold Mushroom House, 1-Cannon | 
| This level is the first level to feature Yoshi, and has another secret exit, which is found by moving to the top of the fields and enter through the pipe. |
| 1-Cannon | World 5-1 | N/A | The Warp Cannon of World 1, leading directly to World 5. It is unlocked by finding the secret exit of the above level. |
| 1-Tower | World 1-4 |  | This is a tower level, featuring swinging platforms and moving stone blocks. Larry Koopa is the boss here. |
| 1-4 | Enemy Area, World 1-5, World 1-6, Red Mushroom House | 
| This is an underwater level, featuring Cheep Cheeps. |
| 1-5 | World 1-Castle | 
| This is first athletic level of New Super Mario Bros. Wii, containing regular and screw-controlled mushrooms, as well as spinning blocks. |
| 1-6 | World 1-Castle | 
| A grassland level containing many rolling hills. Koopa Troopas and Koopa Paratroopas are the main enemies. |
| 1-Castle | World 2-1, World 2-2 | 
| The first castle level of New Super Mario Bros. Wii. It contains lava pools, Thwomps, and giant spinning gears. Larry Koopa is the boss here again. |
