A monowheel or uniwheel is a type of one-wheeled, single-track vehicle. Unlike the unicycle, a monowheel consists of a large, hollow wheel that loops above and around the driver. Monowheels are typically powered by an engine as with a motorcycle, with a chassis securing the steering, driver's seat, and propulsion mechanism to the interior of the wheel.

A unicycle is a vehicle that touches the ground with only one wheel. The most common variation has a frame with a saddle, and has a pedal-driven direct-drive. A two speed hub is commercially available for faster unicycling. Unicycling is practiced professionally in circuses, by street performers, in festivals, and as a hobby. Unicycles have also been used to create new sports such as unicycle hockey. In recent years, unicycles have also been used in mountain unicycling, an activity similar to mountain biking or trials.