In 2005, Atwell made her professional stage debut as Io, a human lover of Zeus, in a new version of Aeschylus’s tragedy at the now-defunct Sound Theatre in London. David Oyelowo starred in the title role.

The following year, Atwell made her Royal Shakespeare Company debut in Thomas Middleton’s Jacobean tragedy Women Beware Women as Bianca, a noblewoman who ran away from her rich family to elope with the poor Leantio. Downton Abbey's Penelope Wilton co-starred as the conniving Livia.

Marking her debut with London's prestigious National Theatre, Atwell starred in Nicholas Hytner’s modern-dress staging of George Etheredge’s Restoration comedy as Belinda, who was reimagined in the production as a publicist in London's Soho district.

In 2008, Atwell returned to the National to play the demanding title role in George Bernard Shaw’s Major Barbara. The idealistic young woman serves the poor of London's East End with the Salvation Army and is disillusioned when the mission accepts a donation from her arms-dealer father.

The following year, Atwell played Catherine in Arthur Miller’s A View from the Bridge. Alongside Ken Stott as Eddie and Mary Elizabeth Mastrantonio as Beatrice, Atwell made a strong impression, earning her first Olivier Award nomination.

In 2011, Atwell starred at the Royal Court in the premiere of Alexi Kaye Campbell’s play about the tensions between faith and capitalism. Atwell played Sophie, who breaks up with her boyfriend Tom over his ethically questionable business activities.

Atwell appeared in the 2013 West End revival of Alexi Kaye Campbell’s first play, set in the present day and in the 1950s, prior to the decriminalization of homosexual relationships between men. Atwell played Sylvia, who is married to a gay man.

LondonTheatre.co.uk’s reviewer admired the “flawless acting from a very fine ensemble and sensitive direction from Jamie Lloyd.” Atwell was rewarded with an Olivier Award nomination for her performance.

Five years later, Atwell returned to the stage at London’s Hampstead Theatre in Sarah Burgess’s satire about high finance in New York. LondonTheatre.co.uk’s reviewer praised the “brittle, poised and polished performances from Hayley Atwell, Aidan McArdle and Tom Riley as the three financiers.”

Josie Rourke’s 2018 production of Shakespeare’s “problem play” at the intimate Donmar Warehouse featured a fascinating twist: in the first half, Atwell played the novice nun Isabella and Jack Lowden was the predatory politician Angelo. However, in the second half, Isabella held the position of power, and the celibate Angelo became her prey.

LondonTheatre.co.uk’s reviewer remarked that “Atwell's Isabella covers a huge spectrum, from her innocent purity to being steely, scheming and unyielding.” The production marked Atwell’s professional Shakespeare debut.

The following year, Atwell appeared in Duncan Macmillan’s new version of Henrik Ibsen’s Rosmersholm as the passionate Rebecca West, who becomes embroiled in an intense relationship with her late best friend’s widower (Tom Burke).

According to LondonTheatre.co.uk’s reviewer, “Ian Rickson's powerful production amplifies the contrast between the reserved anguish of Burke's handsomely bearded Rosmer and the wilder impulses for change being articulated by Atwell.” She received her third Olivier nomination for her fervent performance.

In 2025, Atwell starred as the clever and merry Beatrice in Jamie Lloyd’s party-themed production of Much Ado About Nothing opposite fellow Marvel Cinematic Universe star Tom Hiddleston as Benedick. Both were nominated for Critics' Circle Awards for their performances — and we wonder if more honors will come when the show transfers to Broadway this fall.

LondonTheatre.co.uk’s reviewer was enchanted by Atwell’s performance, calling her a “quick-witted, passionate, uncompromising force of nature, but she is capable of profound stillness too [...] When she realises that Benedick now loves her, and that she might be able to open herself up again, Atwell conjures the most extraordinary sense of wonder as she simply walks down the stage.”

Atwell now makes her Broadway debut in this production. “A star danced and under that I was born,” Beatrice remarks, and a new star is soon to dance on Broadway.

Check back for information about Much Ado About Nothing tickets on New York Theatre Guide.