Sega Carnival is an unlockable track in Sonic Riders. It can be unlocked after being awarded a gold emblem from the Hero Grand Prix. This track is not available in Story Mode and can only be played in other race modes (Time Attack, Free Race etc.).
The track takes place at daytime. Each part of the track is based on other Sega themes. The beginning is set in a city from the Samba de Amigo series, with jumpy and lively buildings, and people cheering the player or any of the other racers on. As players continue, they will go through areas from other Sega franchises: a pirate ship from Billy Hatcher and the Giant Egg, a castle from Nights: Into Dreams, a waterfall from Super Monkey Ball, and finally the city from Crazy Taxi. Upon first entering each part of the course, a jingle from the area's corresponding series plays, like how a "Samba de Amigo!" shout can be heard when entering the carnival at the beginning of the course. The last part of the track features a controlled shortcut, in which Crazy Taxi's Axel takes the player on a ride in his taxi cab through a detour in the city.