Ann Thetis Blacker (13 December 1927 – 18 December 2006) was an English painter and singer. She was noted for her richly coloured pictures, especially using the batik dyed fabric process. Thetis Blacker was born in Holmbury St Mary, Surrey, England. She was the daughter of Carlos Paton Blacker, a psychiatrist, and granddaughter of Carlos Blacker, a friend of Oscar Wilde. Blacker intended to be a singer and studied with the German mezzo-soprano singer Elena Gerhardt in London. Blacker appeared in the chorus at Glyndebourne opera in the 1950s and sang the role of Mother Goose (a whore) in The Rake's Progress by Igor Stravinsky. However, she studied at the Chelsea School of Art in London to become a painter and was taught by the wife of the artist Leonard Campbell Taylor, Brenda Moore.