Terry Alan Kath (January 31, 1946 – January 23, 1978) was an American musician and songwriter, best known a founding member of the rock band Chicago. He played guitar and sang lead vocals on many of the band's early hit singles. He has been praised by the band for his guitar skills and Ray Charles-influenced vocal style. Growing up in a musical family, Kath took up a variety of instruments in his teens, including the drums and banjo. He played bass in a number of bands in the mid-1960s, before settling on the guitar when forming the group that became Chicago. His guitar playing was an important component of the group's sound from the start of their career, and he sang lead on several of the group's singles. He used a number of different guitars, but eventually became identified with the Fender Telecaster fitted with a humbucker pickup and decorated with numerous stickers. Kath was also said to be Jimi Hendrix's favorite guitarist.

Kath struggled with health issues and drug abuse towards the end of the 1970s. He died in January 1978 from an accidental gunshot wound to the head. The bereavement tempted Chicago to consider disbanding, but they ultimately decided to resume as is signified by their memorial song "Alive Again". To commemorate his musicianship, they issued the 1997 album, The Innovative Guitar of Terry Kath.