Harriet Slater

At just six years old, she took to the stage at the Little Theatre in Leicester to overcome her shyness. She wasn't chasing fame in Hollywood or million-dollar streaming deals. She was looking for an escape from childhood anxiety, supported by a family deeply involved in amateur theater.

That amateur discipline helped her gain admission to the Guildford School of Acting, where she completed her training in 2016 before stepping into the British theater circuit. She made her professional debut that same year in Plymouth in the play The Man with the Hammer.

She joined the Royal Shakespeare Company in 2017, playing Rose in the production of Vice Versa.

Auditions in London were tough and small roles were scarce, but her stage training gave her a technical polish that television cameras were quick to notice.

From the Gotham underworld to the nineteenth-century corset

In 2019, she landed her first major on-screen role when she joined the cast of Pennyworth, the TV series about Batman's butler in his younger years. She played Sandra Onslow, a London nightclub singer.

Her character was originally planned as a short secondary storyline, but the producers decided to move her to the main cast after the first season. She stayed for thirty episodes until the series was canceled in 2022.

And the gamble paid off.

That work on American cable television opened the door to Julian Fellowes. In 2024, she took on the lead role in Belgravia: The Next Chapter, playing Clara Dunn, a woman caught in the social machinery of Victorian aristocracy.

Filming required weeks of shoots at historic locations across England, with period costumes weighing more than eighteen pounds.

Commercial horror and the Scottish universe

Film first called on her for a testimonial role in Indiana Jones and the Dial of Destiny in 2023. A year later, she led the cast of Tarot, a horror production for commercial theaters produced by Sony Pictures that grossed nearly $50 million at the global box office.

In 2025, she took on the role of Ellen MacKenzie in Outlander: Blood of My Blood.

Filming for this prequel took place in Glasgow under extreme weather conditions. The production spent nine months shooting on location in Scotland before the network Starz scheduled its international release.