The UFO is an obstacle, firstly introduced on Ninja Warrior UK 2, as the second obstacle in Heat 3, and has been used on several Ninja Warrior's international formats (including Ninja Warrior Sweden and Australian Ninja Warrior), but hasn't been used on American Ninja Warrior.
In essence, competitors must slide down a flying saucer-shaped disk (the disk is the same as the one used on the Area 51, which was used as the seventh obstacle in Stage Three on American Ninja Warrior 7), then timed their release to grab a rope and reach the landing platform to advance.
Several Ninja Warrior's international formats had been used and modified the obstacle, in order to make the obstacle harder:
- For the UFO on Ninja Warrior UK 3, the rope was removed, requiring the competitors to time their release from the disk to the landing platform.
- For the UFO on Ninja Warrior UK 5 and Australian Ninja Warrior 2 (called as the UFO Slider), the track was made similar to the one used on the Cannonball Drop.