Eileen Atkins was born in London and attended the Guildhall School of Music and Drama. Her initial London stage appearance was in Robert Atkins' staging of Love's Labour's Lost at the Open Air Theatre in Regents Park.
Seasons in repertory followed, including two years with the Royal Shakespeare Company at Stratford-upon-Avon. She went on to star at the Old Vic in many Shakespearean roles, among them Miranda and Viola.

Venturing into contemporary plays, Atkins starred opposite Laurence Olivier and Alec Guinness, among others. She won the 1965 London Evening Standard award for Best Actress for her performance as Childie in The Killing of Sister George, and then made her New York stage debut in the play.

Her wealth of U.K. stage credits also includes the title roles of Saint Joan and Medea. She played in T.S. Eliot's The Cocktail Party with Alec Guinness for which she won the London Critics Award. She won a Variety Club Award for her role as Elizabeth in Robert Bolt's Vivat! Vivat! Regina!,and won the London Critics Circle Award and received an Olivier Award for her performance in Peter Hall's staging of A Winter's Tale.

In 1989, Atkins garnered unanimous acclaim for her one-woman show A Room of One's Own, in which she portrayed Virginia Woolf. The off-Broadway production brought her a Drama Desk award for Best Solo Performance and a special citation from the New York Drama Critics Circle.

She then toured the United States in the show, later taping the project for U.K. television on location at Girton College, Cambridge (the venue of Ms. Woolf's original lecture, which inspired the play). She would return to the role in 1992 with Vita & Virginia, which she wrote and starred in (opposite Penelope Wilton as Vita Sackville-West) for the United Kingdom stage as well as in the United States (opposite Vanessa Redgrave). The latter production earned her the New York Critics Circle Award and the Drama Desk Award.

Among her recent stage credits are, in the United Kingdom, Anthony Page's staging of Edward Albee's A Delicate Balance (which brought her another Evening Standard award) and, also in New York, Matthew Warchus' staging of Yasmina Reza's The Unexpected Man. Her performance earned her an Olivier Award for Best Actress.