Born in Coventry, she came of a theatrical family, her brother Fred Terry and several of her other siblings being actors. She first appeared on stage as a child. In 1864, aged only seventeen, she married the painter George Frederick Watts. However, the birth of her son, Gordon Craig, in 1872, was the result of a liaison with Edward Godwin, who later deserted her, having enforced her temporary retirement from acting.
From 1874 she became the leading Shakespearean actress in London, and in partnership with Henry Irving became successful in England and the USA. In 1876 she married Charles Kelly. In 1903 she formed a theatre management business with her son, abandoning Irving. She struck up a friendship and a famous correspondence with George Bernard Shaw. In 1907 she married American actor James Carew. She became a Dame Commander of the British Empire (DBE) in 1925.
Her nephew, Sir John Gielgud, also became an actor. The singer, Helen Terry, is one of her descendants.