William Emanuel Cobham Jr. is a Panamanian–American jazz drummer who came to prominence in the late 1960s and early 1970s with trumpeter Miles Davis and then with the Mahavishnu Orchestra.

The Mahavishnu Orchestra was a jazz fusion band formed in New York City in 1971, led by English guitarist John McLaughlin. The group underwent several line-up changes throughout its history across its two periods of activity, from 1971 to 1976 and from 1984 to 1987. With its first line-up consisting of musicians Billy Cobham, Jan Hammer, Jerry Goodman, and Rick Laird, the band received its initial acclaim for its complex, intense music consisting of a blend of Indian classical music, jazz, and psychedelic rock as well as its dynamic live performances between 1971 and 1973. Many members of the band have gone on to acclaimed careers of their own in the jazz and jazz fusion genres.