Can You Play as Bowser in Super Mario Bros. Wii?

No, you cannot play as Bowser in Super Mario Bros. Wii. Playable characters: Mario, Luigi, Peach, Toad.

Ways to Play as Bowser in Other Games

• Super Mario Bros. U Deluxe: "Bowser's Fury" mode—control Bowser Jr. chasing giant Bowser.
• Super Smash Bros. Series: Bowser is playable fighter.
• Mario Kart Series: Bowser is playable racer.
• Mods (Unofficial): Possible for Super Mario Bros. Wii but risk game file damage.

While not in the original game, Bowser is playable in many other Mario titles.