Ayres was born in 1930 in Barnes in south-west London. She studied at the Camberwell School of Art where figurative art was promoted, which Ayres hated. She left in 1950 and began to paint abstracts, her first solo show was in 1956 at Gallery One. Ayres was closely involved with leading British abstract artists such as Howard Hodgkin, Robyn Denny and Roger Hilton. She taught at St Martin's School of Art for 12 years before becoming Head of Painting at Winchester School of Art in 1978; in 1981 she resigned, leaving London to live in Wales. Ayres was made an OBE in 1986, and in 1991 became a Royal Academician. She later temporarily resigned from the Academy, in part because of the controversial Sensation exhibition hosted by the Academy in 1997. Her solo shows are an impressive list: Museum of Modern Art, Oxford, 1981; Serpentine Gallery, 1983; and the Royal Academy in 1997. Her work can be seen on display at the Alan Cristea Gallery in London. Ayres was shortlisted for the Turner Prize in 1989. She married, and then divorced, the painter Henry Mundy. They had two sons.