Kathryn "Kathy" Valentine (born January 7, 1959, Austin, Texas) is an American bass guitarist, best known for her work in The Go-Go's.
Valentine began playing at age 16 in her hometown of Austin, and joined a fledgling Girlschool in London, England in 1975. In 1978, Valentine relocated to Los Angeles, California and co-founded The Textones with Carla Olson.
She joined the Go-Go's on New Year's Eve 1980, as a substitute for an ailing bassist, but was asked to remain as a permanent member shortly thereafter. She wrote "Can't Stop the World" on the Go-Go's debut album, and co-wrote the hit singles, "Vacation", "Head over Heels", and "The Whole World Lost Its Head" which appeared on subsequent releases. After the Go-Go's disbanded for the first time in 1985, Valentine played guitar in the World's Cutest Killers with former Girlschool guitarist Kelly Johnson.
In 2005, she released a solo recording, Light Years, that she co-produced, wrote, arranged and performed the guitar and vocal tracks. She now resides in her hometown of Austin with her daughter. Valentine played with the Go-Go's for 31 years, had a solo band; the Impossible, played guitar in the Delphines with Dominique Davalos and different drummers. She now plays with a new line-up of BlueBonnets, is a student majoring in English, working as a writer, and has taken opportunities to be a public speaker at a variety of events.