[4] In 1979, Foster starred in the world premiere of Andrew Davies's Diary of A Desperate Woman at the Belgrade Theatre in Coventry, England.
[5] That same year she became a resident actress at the New Wolsey Theatre; making her debut with the company in a production of Carlo Goldoni's 1746 play The Servant of Two Masters.
[6] Other roles she performed at that theatre included Diana in the world premiere of Anthony Burgess's The Eve of Saint Venus (1979),[7] Gerda in a stage adaptation of Hans Christian Andersen's The Snow Queen (1980),[8] and Hermia in William Shakespeare's A Midsummer Night's Dream (1980).
[10] She had a critical triumph as Nora Helmer in Henrik Ibsen's A Doll's House at The Dukes, Lancaster in 1981; a production which used a new contemporary English language translation by playwright Pam Gems.
The Stage theatre critic Robin Duke wrote "Given the contemporary nature of the new translation, the play compounds its earlier feminist ideals and clenches a new iron fist in a velvet glove.
[14] Reviewing the latter performance, The Guardian theatre critic Robin Thornber stated, "Joanna Foster makes Stella a true star of the play, all sweet reason and patience, torn for compassion both for her sister's sensitivity and her husband's animal pride.
In 1982, Foster starred as Armand in the Royal Shakespeare Company's production of Mikhail Bulgakov's Molière at The Other Place in Stratford-upon-Avon;[16] a performance described as "alluring" by The Observer.
[27] In 1991, Foster created the role of Galina in the world premiere of Olwen Wymark's Brezhnev's Children with the Moving Target Theatre Company; a work based on Julia Voznesenskaya's 1987 Russian novel The Women's Decameron.
[40][41] She is the fourth actress to portray the role of Susan Barlow in Coronation Street, after Katie Heannau, Wendy Jane Walker and Suzy Paterson.