Sonic & All-Stars Racing Transformed (ソニック&オールスターレーシング トランスフォームド,Sonikku ando Ōru-Sutāzu Rēshingu Toransufōmudo?) is the fourth installment in the Sega All-Stars series of games and the second racing game in the series. It is the sequel to Sonic & Sega All-Stars Racing. Like the previous twogames, it features content from the Jet Set Radio series.
The gameplay for Sonic & All-Stars Racing Transformed is nearly identical to the previous game. However, this time the vehicles transform while either launching into the air or racing on water. As such, each character has a car, plane, and boat in one vehicle. All star moves and items come back from the previous game with some new ones as well. The game can be played up to 4 people via local multiplayer or eight people via online multiplayer. Like before, character's have special moves known as "All-Star Moves", that can help them catch up with the competition if left behind.