From Leicester to the Highlands: Harriet Slater on GSA, craft, community and becoming Ellen MacKenzie
When Harriet Slater arrived at the Guildford School of Acting (GSA) to audition for the BA Acting course, she had no roadmap, no insider guidance and, as she puts it, was “really green to the whole drama school thing.” What she did have was instinct, excitement, and a confidence that has carried her from youth theatre to leading roles in Belgravia: The Next Chapter (MGM+), Pennyworth (HBO Max), and most recently, global phenomenon Outlander: Blood of My Blood (Starz).
Today, Slater is one of GSA’s most recognisable recent alumni. Looking back, she credits the School not just with skill development, but with lifelong friendships, key professional connections, and the start of a journey that has made her both a screen actor and an artist dedicated to continuous learning.
Harriet graduated from Guildford School of Acting with a BA in Acting in 2016.
Choosing GSA: “I got a really great vibe.”
Harriet’s decision to study at GSA was instinctive. The audition day stood out for its warmth, its structure and the sense of creativity it offered.
“I loved the audition day at GSA. It was a full day workshop which was unlike most of my other auditions. I got a really great vibe off the School, that’s why I chose to go.” She adds, with her characteristic honesty, “also, to be honest, it was the only one I actually got into!”
What she didn’t know then was that she was stepping into a community that would shape her personally and professionally for years to come.
A training ground and a friendship network for life
For all the techniques, classes and productions, it’s the people Harriet remembers most vividly.
It never felt competitive... it felt very supportive.
“My main takeaway is the friends that I made, who are still some of my closest friends today. It never felt competitive with them, it always felt very supportive.”
That support network has endured far beyond graduation – flat-shares, weddings, daily group chats and built-in self-tape partners among them. “I lived with GSA friends right up until I moved up to Glasgow for Blood of My Blood,” she explains. “We're still very much in touch every day and celebrate each other's achievements all the time.”
Some lessons from GSA have stayed with her too. She recalls external director Justin Audibert advising the cast before a third-year show: “Have fun and don't carry any baggage. If something goes wrong, leave it in that scene don't bring it into the next.”
That advice stuck with her and inspired a “learn from your mistakes and keep moving forward” approach to her career.
She landed her first professional acting job before she’d even graduated – The Man with the Hammer at Plymouth Theatre Royal. “After working together at GSA, Justin asked me to audition. Through that job I found my agent and went on to work with the same writer the following year at the Royal Shakespeare Company. I owe a lot to Justin and to GSA for getting him in.”
From youth theatre to screen: learning by doing
Harriet grew up firmly rooted in Leicester’s vibrant youth theatre and amateur dramatics scene – first at The Little Theatre, then at Curve – an environment she describes as foundational to her love of performing. “I absolutely loved it; I did at least one show a year and it provided me with such a wealth of experience and a solid foundation and love of the craft.”
Her transition to screen wasn’t immediate. Although her GSA training focused heavily on stage, she found herself auditioning frequently for screen roles without quite knowing how to shift her technique.
“I realised that I was doing stage acting. It was coming across well in the room, but it wasn't coming across well on the screen.”
What followed was a period of intense self-training: screen classes, casting workshops, and hours of studying performances. “I learned so much from watching other people. I got really nerdy; if I had access to the script, I’d read a scene and then I'd watch the scene.”
Her big break on screen came in Pennyworth, though it brought a crash-course in the realities of filming. “I felt like the biggest imposter; when I started, I couldn't even hit a mark!” But over three seasons the role grew dramatically, giving her an opportunity to hone her skills – proof, she says, that “you never know what's around the corner, or where it’ll take you. I’m beyond grateful for that experience.”
Tips for current GSA students: “Don't be hard on yourself”
Harriet is an actor who works with intention. She journals after every audition and every day on set, writing down “what went well and what I learnt. I find that helps with leaving the day there and moving on. In the beginning, I found that very difficult to do. But everything gets easier with practice.”
Training doesn't end when the three-year degree ends.
Her advice to current – and future – GSA students:
Be a sponge.
“Training doesn’t end when the three-year degree ends – keep learning every single day.”
Detach from comparison.
“Competition is not necessarily an unhealthy thing as long as it drives you, but don't be hard on yourself. I try not to compare myself to others and am always striving for self-improvement.”
Control what you can, release what you can’t.
“Often, whether or not you get the job is down to factors completely out of your control. With that knowledge in mind, prepare as best you can and then let it go. What’s for you won’t go by you.”
Embrace “failing forward.”
“You often learn your biggest lessons through failure, which means it isn’t actually failure. Fail and fail and fail again!”
Celebrate the small wins.
“In an industry where constant work is rare, I think it’s important to recognise every achievement. Just being seen for a role is an opportunity to do what we love - revel in it!”
Be brave at drama school.
“If I had my time again, I’d push myself to get up and do the thing I’m scared of, to be braver and to take more risks. Those three years go by so quickly - squeeze every last drop out of them.”
Ellen MacKenzie and the world of Blood of My Blood
Harriet’s role as Ellen MacKenzie (Jamie Fraser’s mother) in the Outlander prequel has propelled her into the heart of a global fanbase. She admits she hadn’t watched the original series before auditioning, but the scale of the fandom became clear the moment she stepped onto the stage at San Diego Comic-Con in July 2025, prior to the premiere of Blood of My Blood.
“There were thousands of people in that hall, who were so excited and loyal to the world… It made me feel very, very lucky to be part of something that means so much to so many.”
Playing Ellen has also given her unexpected creative freedom. “We've heard a bit about my character, but unlike some of the other characters in the show, we've never seen her before. It definitely feels like I have the space to make her my own. But the writing does so much of the work for me - she’s a force!”
Looking ahead, she confirms that series two reveals new depths to Ellen: “She has her own battles to fight, which in many ways make her even stronger.”
What’s next?
Alongside returning for Blood of My Blood, Harriet has completed filming Fall 2, a survival thriller shot in Thailand – complete with intense stunt work and blistering heat. “It couldn't be more different. I'm excited to see how it turns out!”
She also dreams of returning to the stage and one day taking on Lady Macbeth, the monologue she auditioned for drama school with, as she says, “there's nothing like the thrill of a live audience”.
“Why not me?”
Harriet’s career is built on graft, curiosity, and the refusal to let self-doubt lead the way. She still remembers her school careers adviser telling her “It’s a tough industry… hardly anyone makes it.” Her response? “Well, if not me, who?”
It’s a spirit she hopes GSA students will carry with them – alongside, kindness, generosity, and the knowledge that no two paths in this industry are ever the same.