Alphonso Johnson (born 2 February 1951) is an American jazz bassist active since the early 1970s. Johnson was a member of the influential jazz fusion group Weather Report from 1973 to 1975, and has performed and recorded with numerous high-profile rock and jazz acts including Santana, Phil Collins, members of the Grateful Dead, and Chet Baker.

Born in Philadelphia, Pennsylvania, Johnson started off as an upright bass player, but switched to the electric bass in his late teens. Beginning his career in the early 1970s, Johnson showed innovation and fluidity on the electric bass. He sessioned with a few jazz musicians before landing a job with Weather Report, taking over for co-founding member Miroslav Vitous. Johnson debuted with Weather Report on the album Mysterious Traveller. He appeared on two more Weather Report albums: Tale Spinnin’ (1975) and Black Market (1976) before he left the band to work with drummer Billy Cobham. During 1976-77 he recorded three solo albums as a band leader, for the Epic label, in a fusion-funk vein.