Christopher Russell Edward Squire (4 March 1948 – 27 June 2015) was an English musician, singer and songwriter best known as the bassist and backing vocalist of the progressive rock band Yes. He was the longest-serving original member, having remained in the band until his death and appearing on every studio album released from 1969 to 2014. In 2017, he was posthumously inducted into the Rock and Roll Hall of Fame as a member of Yes.

Squire was widely regarded as the dominant bassist among the English progressive rock bands, influencing peers and later generations of bassists with his incisive sound and elaborately contoured, melodic bass lines. His name was associated with his trademark instrument, the Rickenbacker 4001 (British model RM1999). From 1991 to 2000, Rickenbacker produced a limited-edition signature model bass in his name, the 4001CS.