The Sons of Champlin are an American rock band, from Marin County, California, in the San Francisco Bay Area, formed in 1965. They are fronted by vocalist-keyboardist-guitarist Bill Champlin, who, after leaving the group in 1977, joined the rock band Chicago from 1981 to 2009, reforming the Sons of Champlin in 1997. They brought to the late ‘60s music scene in the Bay Area a soulful sound built around a horn section, Hammond B3 organ, sophisticated arrangements, philosophical themes, Bill Champlin's songwriting and blue-eyed soul singing, and Terry Haggerty's unique jazz-based guitar soloing. They are one of the enduring 1960s San Francisco bands, along with Jefferson Airplane, the Grateful Dead and Moby Grape.

William Bradford Champlin is an American singer, keyboardist, guitarist and songwriter. He formed the band Sons of Champlin in 1965, which still performs today, and was a member of the rock band Chicago from 1981 to 2009. He performed lead vocals on three of Chicago's biggest hits of the 1980s, 1984's "Hard Habit to Break" and 1988's "Look Away" and "I Don't Wanna Live Without Your Love". During live shows, he sang the lower, baritone, vocal parts originally performed by founding guitarist Terry Kath, who had died in 1978. He has won multiple Grammy Awards for songwriting.