Douglas Ray "Cosmo" Clifford (born April 24, 1945, Palo Alto, California), is an American rock drummer best known for playing with the rock band Creedence Clearwater Revival. An early influece on Clifford was The Beatles appearance on The Ed Sullivan Show. "They were a quartet and we said, wow, we can do that. If these guys from England can come out and play rock 'n' roll, we can do it ... We bought Beatle wigs. We went to the drama store, and I guess they were Three Stooges wigs at that time."
After Creedence Clearwater Revival broke up, Clifford and former CCR bassist Stu Cook joined Don Harrison in the Don Harrison Band, and also issued a solo album called Cosmo.
In 1995, Clifford and Cook formed the band Creedence Clearwater Revisited.