Between her buzzy role in House of the Dragon and her move to dark comedy with Sirens, the&nbsp;Supergirl&nbsp;actress is Hollywood's new favorite icon.

Milly Alcock&rsquo;s portrayal of a young Rhaenyra Targaryen in House of the Dragon&nbsp;cemented her as an actor to watch. Starring in arguably the most anticipated prequel in modern television history is a career feat that most actors dream of achieving. Alcock has done that and more before the age of 30. This year, she&rsquo;s taken on a more mature role in the hit Netflix miniseries Sirens, starring alongside Julianne Moore and Meghann Fahy. Fans of the Game of Thrones universe may find the 25-year-old actor unrecognizable as Simone DeWitt, the docile, golden-blonde assistant to an eerily alluring billionaire, Michaela Kell (Moore). Despite Sirens being relatively new, the show has already cultivated a strong fan base. And, like any widely beloved limited series, rumors of a second season are circling the internet. Netflix has not confirmed any plans to renew the show, but we&rsquo;re keeping our eyes peeled.&nbsp;
Now Alcock is starring in the upcoming&nbsp;Supergirl&nbsp;movie as she tries her hand in a new mystical universe, the DC universe that is. The movie is set to premiere on June 26, 2026, and Alcock will portray the titular role of Supergirl. Before House of the Dragon&nbsp;and&nbsp;Supergirl,&nbsp;Alcock climbed the acting ranks with other roles, and L'OFFICIEL has rounded up all the interesting facts about Alcock's blooming career and young life.&nbsp;

<h3 style="text-align: center;">She had never watched Game of Thrones when she auditioned for House of the Dragon.</h3>

HBO sent Alcock a redacted script for her self-tape audition, but her friend quickly figured it out, she told The London Standard in an <a href="https://www.standard.co.uk/culture/tvfilm/milly-alcock-interview-house-of-the-dragon-game-of-thrones-b1019190.html">interview</a>. &ldquo;I did not know that you could make television like this,&rdquo; she said.

<h3 style="text-align: center;">She&rsquo;s set to portray Supergirl in the Supergirl: Woman of Tomorrow.</h3>

Milly Alcock at TAG Heuer Carrera 60th Anniversary Party. Getty Images.

CEO of DC Studios James Gunn confirmed the casting on Instagram, writing that he was &ldquo;blown away by her varied auditions and screen tests for #Supergirl. She embodies Kara as envisioned by [Supergirl: Woman of Tomorrow author Tom King], [Supergirl: Woman of Tomorrow illustrator Bilquis Evely], and Ann Nogueira [the film&rsquo;s screenwriter]. The film adaptation will be in theaters next June.

<h3 style="text-align: center;">An HBO executive told her she needed an &ldquo;acting coach&rdquo; while on the set of House of the Dragon.</h3>

Milly Alcock on 'The Tonight Show' with Jimmy Fallon in 2025. Getty Images.

While on The Tonight Show, Alcock shared the low moment in her early days of filming the HBO fantasy show. &ldquo;It just confirmed everything that I kind of know to be true &hellip; that I&rsquo;m not very good at my job,&rdquo; Alcock said. Jimmy Fallon quickly assured the actor, stating she was a &ldquo;fan favorite&rdquo; among audiences.

<h3 style="text-align: center;">She started acting professionally at 13.</h3>

Milly Alcock at the 80th Golden Globe Awards. Getty Images.

Alcock got her first acting credit portraying an unnamed teenage girl in the television series Wonderland, per IMDb. She&rsquo;s appeared in eleven television shows since. Supergirl: Woman of Tomorrow&nbsp;will be her second feature film.&nbsp;

<h3 style="text-align: center;">She attended Newton High School of the Performing Arts.</h3>

Milly Alcock at Glastonbury in June 2025. Getty Images.

The actor dropped out after landing a starring role in the Australian drama series Upright. Alcock also landed her first recurring role in 2017 in the miniseries High Life. After these two debuts, Alcock began making more appearances on screen in shows like The School, Reckoning, The Gloaming, and many others.&nbsp;

<h3 style="text-align: center;">She appeared in a Noel Gallagher music video.</h3>

Milly Alcock at All Points East Festival 2022. Getty Images.

Alcock loves punk music, and she starred in Noel Gallagher's Easy Now&nbsp;music video when she was 21 years old. The music video was released in January 2023, and Alcock plays a rebellious teenager, recklessly running through the streets of London searching for her freedom. Gallagher watches from the sidelines as Alcock's character disrupts pigeons and jumps on cars until she eventually finds liberation and joy.&nbsp;

<h3 style="text-align: center;">She starred in&nbsp;The Crucible&nbsp;on London's West End</h3>

Milly Alcock at the Academy Museum Gala in October 2025. Getty Images.

From June 7 through Sept. 2, Alcock portrayed Abigail Williams in the National Theatre's production of The Crucible&nbsp;at the Gielgud Theatre. This performance marked her professional theatre stage debut, and this debut followed her breakout performance in House of the Dragon.&nbsp;

<h3 style="text-align: center;">Alcock was named a rising star at 13.&nbsp;</h3>

Milly Alcock at 'House of the Dragon' World Premiere. Getty Images.

When Alcock was 13 years old, she was named a rising star by the Casting Guild of Australia in 2018 for her role as Meg in the series Upright. This honor was just the beginning of her acting journe,y and she would soon be recognized for her role in House of the Dragon.&nbsp;

<h3 style="text-align: center;">Cate Blanchett and Audrey Hepburn inspired Alcock's portrayal of Rhaenyra.&nbsp;</h3>

Milly Alcock speaking at Newport Beach Film Festival in 2025. Getty Images.

When Alcock talks about her inspiration for her character Rhaenyra in House of the Dragon, she often mentions that she feels like her character is a beautiful mix of Audrey Hepburn and Cate Blanchett. To her, Rhaenrya is cheeky and witty and always has to put up a regal front, but deep down, she's actually uncomfortable in her skin. When channeling these feelings for her character, Alcock thinks back to Blanchett and Hepburn.&nbsp;

Who Is Milly Alcock? Everything to Know About the 'Supergirl' Star

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