2016–2022: Early work Ramsey made their professional debut at age 11 as young noblewoman
Lyanna Mormont in the
HBO fantasy drama series
Game of Thrones (2016–2019). Ramsey later said that the set "felt very natural" and immediately like a place where they belonged. After their debut in the
sixth-season episode "
The Broken Man", critics and viewers praised Ramsey's portrayal of a no-nonsense leader at such a young age. Co-showrunner
D. B. Weiss said that Lyanna was originally intended to appear in only one scene, but Ramsey's performance led the production team to expand the character into a recurring supporting role. Following their appearance in
the season finale,
The Hollywood Reporter described Ramsey as the sixth season's breakout star. Ramsey continued in the role for the show's
seventh and
eighth seasons. While appearing on
Game of Thrones, Ramsey also took on their first leading television role as
Mildred Hubble in the
CBBC fantasy drama series
The Worst Witch (2017–2019). During filming of the first series, Ramsey developed
anorexia nervosa, partly due to the anxiety of spending long periods away from home while still young. They also struggled with
emetophobia. Although they had largely recovered from anorexia by the third series, Ramsey decided not to return and the role was recast with
Lydia Page for the fourth and final series. During breaks from filming
Game of Thrones and
The Worst Witch, Ramsey took on supporting roles in several short and feature-length films, including the psychological drama
Two for Joy (2018), the comedy
Holmes & Watson (2018), and the biographical drama
Judy (2019). Ramsey also expanded into voice acting with their portrayal of the title character in the Netflix animated series
Hilda (2018–2023) and television film
Hilda and the Mountain King (2021). The series won three
Daytime Emmy Awards, and Ramsey earned nominations for Best Voice Performance at the British Animation Awards in 2020 and 2022. Ramsey also contributed musically by writing and performing the song "The Life of Hilda" for the show's second series. Ramsey next played the orphan Elsbeth in the biographical drama
Resistance (2020), Although the film received mixed reviews,
TheWraps Michael Nordine praised Ramsey's performance as "expressive" and "affecting" and wrote that "great things can be expected of the teenage thespian in the future". Later that year, Ramsey appeared in the second series of the HBO fantasy drama
His Dark Materials (2020). Casting director Kahleen Crawford recalled that Ramsey and co-star
Ella Schrey-Yeats's performances as
Angelica and Paola, respectively, led to the roles being expanded to provide additional screen time. the horror-drama
Requiem (2021), in which they appeared alongside fellow Television Workshop alumni
Safia Oakley-Green, and
Villain (2023). Ramsey's next television role was
Lady Jane Grey in the
Starz historical drama
Becoming Elizabeth (2022), which chronicles the early years of
Elizabeth I. Megan O'Keefe of
Decider described Ramsey as the "scene-stealer of the cast", while Kristen Lopez of
IndieWire opined that Ramsey's portrayal of Grey was "perfectly played". Although the show received positive reviews, it was cancelled after the first season due to low ratings. Ramsey starred in their first leading film role as Lady Catherine in
Catherine Called Birdy (2022), a medieval coming-of-age comedy written and directed by
Lena Dunham and adapted from the
novel by
Karen Cushman. The film received positive reviews; critic
Mark Kermode described Ramsey as a "thrilling screen presence", while
Rolling Stones David Fear felt that Birdy was "played remarkably and brilliantly by [Ramsey] ... who seems to be a gift from the casting gods". For their performance, Ramsey received a nomination for the
Critics' Choice Award for Best Young Performer. They also wrote and performed "Birdy Song" for the film's soundtrack.
2023–present: International recognition as
Ellie and
Joel in
The Last of Us. Ramsey experienced a career breakthrough with their portrayal of
Ellie in HBO's
post-apocalyptic drama series
The Last of Us (2023–present). During filming of
the first season of the show, Ramsey and co-star
Pedro Pascal (who portrayed
Joel) developed a close friendship. Pascal described Ramsey as "his blessing" and said the two were "linked souls". Critics praised the chemistry between Ramsey and Pascal as well as their individual performances. and
Screen Actors Guild Award. At the time of nomination, they were also the youngest ever
leading actress nominee for a
British Academy (BAFTA) Television Award. For their role, Ramsey was selected for the 2023
BAFTA Breakthrough programme. Ramsey was also included on the
Forbes 30 Under 30 Europe list for 2024.
The second season of
The Last of Us was released in April 2025. With Pascal taking on a reduced role, Ramsey spent much of the season without him and said the experience was "more challenging" and "felt like more weight". Critics praised Ramsey's performance, writing that they shouldered the season's demands and conveyed Ellie's development into young adulthood with depth and nuance. After the success of
The Last of Us, Ramsey portrayed Kelsey Morgan, a pregnant heroin addict, in the second series of the
BBC prison drama
Time (2023). It was the first role Ramsey was offered without an audition and they found it challenging, saying that while earlier roles "came from inside of me, [Kelsey] felt more external". The series received positive reviews, with critics praising Ramsey's "confident" and "transfixing" performance. The role earned them the
Royal Television Society Award for Female Supporting Actor. In the same year, Ramsey returned to voice acting as the young, rebellious Molly in the animated comedy
Chicken Run: Dawn of the Nugget (2023). The film received favourable reviews, with
The Independents Clarisse Loughrey praising Ramsey's "joyous, buoyant performance", and Jacob Oller of
Paste Magazine complimenting them as "the clear star, putting an extra level of fear, awe or disillusionment into [their] few lines". Ramsey also voiced the
artificial intelligence system nTrac in the low-budget
sci-fi film
The Correction Unit (2025), which was filmed in Nottingham and featured emerging actors from the area. During the press tour for the second season of
The Last of Us, Ramsey hinted that they had been working on producing music. In October 2025, singer-songwriter
Matt Maltese confirmed that he had been collaborating with Ramsey, under Ramsey's musical alter ego Bello, for about a year. On 3 October 2025, the pair released a new version of the song "Cure for Emptiness", which first appeared on Maltese's album
Hers (2025). The film had its world premiere at the
76th Berlin International Film Festival. Ramsey said that, initially, they had been wary that the concept of a camp for kids with cancer was "a recipe for disaster", but found that the film subverted their expectations. They described the shoot as "the best weeks of [their] life so far" and credited it with rekindling their enthusiasm for independent cinema. Ramsey next played a supporting role as the voice of Zora, a sheep in the
Amazon MGM mystery comedy film
The Sheep Detectives (2026), about a flock investigating the death of their shepherd, George, played by
Hugh Jackman. The film received generally positive reviews. Ramsey is set to appear as the title character in
Channel 4's drama series
Maya (2026), and as Ella in
Guy Nattiv's psychological thriller
Harmonia. Ramsey will also return as Ellie in
the third season of
The Last of Us, which is planned for release in 2027. Ramsey is set to appear on the
second series of
The Celebrity Traitors in late-2026. == Personal life ==