A wheel series, wheel show, wheel format or umbrella series is a television series in which two or more regular programs are rotated in the same time slot. Sometimes the wheel series is given its own umbrella title and promoted as a single unit instead of promoting its separate components.
The most successful example of a wheel series on American television was the NBC Mystery Movie, which debuted in 1971 on NBC and ran for seven seasons. Three of the shows in the rotation, Columbo, McCloud, and McMillan & Wife, were among the most successful shows on American television in the 1970s.