Milly Alcock, the breakout star who brought young Rhaenyra Targaryen to life in HBO’s House of the Dragon, got a rough welcome to the Game of Thrones prequel. During her first-ever talk show appearance on The Tonight Show Starring Jimmy Fallon on May 19, 2025, the 25-year-old Australian actress shared a story that had the audience gasping: on her second day on set, a “very high up” figure pulled her aside and said, “Um, we’re gonna get you an acting coach.” The comment hit hard, shaking her confidence and making her question if she was cut out for the role. Here’s the lowdown on Alcock’s tough moment and how she turned it into fuel for her rise to stardom.
Alcock, who was plucked from relative obscurity in Australia to play the fierce young princess in the 2022 series, admitted she was already a bundle of nerves stepping into the massive Thrones universe. “I was kind of, like, plucked out of Australia and just, like, thrown in,” she told Fallon, describing the whirlwind of landing the role. “It was very, very terrifying and it kind of changed my life.” So when that unnamed higher-up suggested an acting coach after just one day of filming, it felt like a gut punch.
“It just confirmed everything that I’ve kind of known to be true, [which] is that I’m not very good at my job,” she said with a self-deprecating laugh, adding, “I was like, ‘I can’t do this. This is terrible. This is a big mistake.’” The audience groaned in sympathy, and Fallon, visibly shocked, jumped in to lift her spirits, saying, “From the very first episode, you were a fan favorite. That guy is wrong. You are unbelievable.” He even turned to the camera, jabbing a thumb at Alcock and telling the mystery exec, “Look at her! You’re totally wrong, buddy.”
The comment stung, but Alcock’s performance as Rhaenyra proved the doubter wrong. Critics raved about her, with CNET’s Daniel van Bloom calling her “the shining star of House of the Dragon’s opening episodes” for her “enchantingly expressive face” that captured the tangled emotions of royal politics. She earned a Critics’ Choice Award nomination for Best Supporting Actress, and fans on X went wild for her, with posts like one from @Dinaemyra on May 20, 2025, fuming, “Not a higher up in HOTD telling Milly Alcock that she needs an acting coach?!!! When she eat up all her scenes?!! I need them to crumble!!” Her raw, commanding portrayal helped House of the Dragon snag a Golden Globe for Best Drama Series in 2023, though Alcock humbly brushed off her role in that win, saying, “I didn’t win it!” Fallon shot back, “Yeah, you did. You won. Your show won.”
Looking back, Alcock’s journey to House of the Dragon wasn’t exactly a straight shot. Born in Sydney in 2000, she grew up in a non-creative family and found her spark in a school play at age five or six. She ditched high school at Sydney’s Newtown High School of the Performing Arts in 2018 to star as Meg in the Australian drama Upright, a role that won her a Casting Guild of Australia Rising Star Award. “School’s never been for me,” she told The Sydney Morning Herald. “I couldn’t turn down Upright for a piece of paper.” That grit paid off when she landed Rhaenyra, a role she nabbed while washing dishes at a Sydney restaurant. “I told myself, ‘Okay, for whatever reason they believe in me, so I have to believe in myself,’” she said in a 2022 Wonderland interview.
Despite the early setback, Alcock’s time on House of the Dragon was a game-changer. She starred in Season 1 alongside Emma D’Arcy, Matt Smith, and Rhys Ifans, and made a surprise cameo in Season 2, which streamed on HBO in 2024. Her scenes, especially a haunting moment with Smith’s Daemon Targaryen, left fans emotional, with director Geeta Vasant Patel telling Variety that Alcock and Smith’s trust brought raw depth to the moment. Season 3, now filming with new cast members like Tommy Flanagan and Dan Fogler, won’t feature Alcock, but her impact lingers.
Now, Alcock’s soaring higher than ever. She’s starring in Netflix’s Sirens with Julianne Moore and Meghann Fahy, which dropped on May 22, 2025, and she’s set to play Supergirl in DC’s Supergirl: Woman of Tomorrow, hitting theaters June 26, 2026, with a rumored cameo in Superman this July. On The Tonight Show, she dodged spilling details about Supergirl but charmed the crowd with her story of giggling through the 2023 Golden Globes acceptance speech, blaming free champagne.
That higher-up’s comment may have rattled Alcock, but it didn’t stop her. She turned her nerves into a performance that hooked millions and landed her on Hollywood’s radar. As she told Fallon, she was “absolutely mortified” on set, but you’d never know it watching her rule as Rhaenyra.