Beatrice Tanner was born in London, daughter of John Tanner and his Italian wife. In 1894 she eloped with Patrick Campbell, who died fighting in the Boer War in 1900 (their son also died in action, during World War I). She married her second husband, George Cornwallis West, in 1914.
A fine actress, Mrs Campbell was equally famous for her wit, evidenced in correspondence with her friend George Bernard Shaw, which has been made the subject of many plays and books. She made her stage debut in Bachelors (1888) at the Alexandra Theatre, Liverpool, and her first London appearance at the Adelphi as Helen in The Hunchback (1890). Her real break, however, came at St James's Theatre as Paula Tanqueray in Pinero's The Second Mrs Tanqueray (1893). During the remainder of the decade she appeared in numerous plays, ranging from Shakespeare to Ibsen, most notably as Mélisande in Pelléas and Mélisande at the Prince of Wales's Theatre. This success was repeated with even greater acclaim when the play was performed in French at the Vaudeville (1904) with Sarah Bernhardt (1845–1923) as Pelléas. Mrs Campbell also created the role of Eliza Doolittle in Shaw's Pygmalion (1914). Later she toured the USA and Britain and appeared in minor film roles. Her daughter, Stella Patrick Campbell, also became an actress.