"Monday, Monday" is a 1966 song written by John Phillips and recorded by the Mamas & the Papas, using background instruments played by members of the Wrecking Crew for their 1966 album If You Can Believe Your Eyes and Ears. Denny Doherty was the lead vocalist. It was the group's only #1 hit on the U.S. Billboard Hot 100.

John Edmund Andrew Phillips was an American folk rock musician. He was the leader of the vocal group the Mamas & the Papas and remains frequently referred to as Papa John Phillips. In addition to writing the majority of the group's compositions, he also wrote "San Francisco " in 1967 for former Journeymen bandmate Scott McKenzie, as well as the oft-covered "Me and My Uncle", which was a favorite in the repertoire of the Grateful Dead. Phillips was one of the chief organizers of the 1967 Monterey Pop Festival.