Big O (Ferris wheel)

Big O (ビッグ・オー) is a centerless non-rotating Ferris wheel at Tokyo Dome City in Bunkyo, Tokyo, Japan. Big O has a diameter of 60 m. Tokyo's largest roller coaster, the 130 km/h Thunder Dolphin, passes through the centre of the wheel.

Big O was constructed by Mitsubishi Heavy Industries. Construction was completed in March 2003, and the ferris wheel was opened to the public in May 2003. Big O was listed as the world's first centerless Ferris wheel by Guinness World Records.

Joysound karaoke machines were added to eight of its forty gondolas in August 2017.