Milly Alcock has gone from working in Australian television to becoming one of the most recognizable young actors in Hollywood. She first built attention through Australian productions such as Upright, then reached an international audience as young Rhaenyra Targaryen in HBO’s House of the Dragon. In 2025, she appeared as Kara Zor-El in Superman, and in 2026 she took the lead in DC Studios’ Supergirl. Her recent work also includes Netflix’s Sirens, where she played Simone DeWitt alongside Julianne Moore, Meghann Fahy and Kevin Bacon.
This biography looks at Milly Alcock’s age, early life, education, acting career, major roles, movies, television shows, awards, personal life, Supergirl journey and upcoming projects. It also explains how the actress moved from relatively small Australian productions to major international franchises.
Last updated: August 13, 2026
Milly Alcock Quick Facts
| Detail | Information |
|---|---|
| Full name | Amelia May Alcock |
| Professional name | Milly Alcock |
| Date of birth | April 11, 2000 |
| Age in 2026 | 26 |
| Birthplace | Sydney, New South Wales, Australia |
| Nationality | Australian |
| Profession | Actress |
| Years active | 2014–present |
| Breakthrough role | Young Rhaenyra Targaryen in House of the Dragon |
| Major film role | Kara Zor-El / Supergirl |
| Netflix role | Simone DeWitt in Sirens |
| Notable earlier role | Meg Adams in Upright |
| West End role | Abigail Williams in The Crucible |
| 2026 major award | Critics Choice Super Award for Best Actress in a Superhero Movie |
The 2014–present career date is used here because Wonderland is the earliest credited television appearance listed in her filmography. The earlier “2013” date sometimes repeated in biography databases is not used because it creates an avoidable conflict with the documented 2014 television debut.
Who Is Milly Alcock? Age, Early Life and Career
Milly Alcock is an Australian actress who gained international recognition as young Rhaenyra Targaryen in House of the Dragon. Before her HBO breakthrough, she had already built television experience through Upright, Pine Gap, Fighting Season, A Place to Call Home and Janet King. She later expanded into theatre, film and major productions, including The Crucible and Sirens.
Born on April 11, 2000, in Sydney, Australia, Alcock turned 26 in April 2026. She grew up in Sydney with two younger brothers and attended Newtown High School of the Performing Arts before leaving in 2018 as her acting career developed.
In 2026, she took on her biggest role yet as Kara Zor-El/Supergirl, marking her move into a leading DC superhero role. Her performance also earned her a Critics Choice Super Award for Best Actress in a Superhero Movie.
Early Career
How Milly Started Acting
Milly Alcock began acting as a teenager. Her first credited TV appearance came in 2014 in the Australian romantic comedy series Wonderland.
She also presented Australian Disney Channel programs including B.F. Chefs and Hanging With. In 2017, she appeared as Isabella Barrett in the web miniseries High Life.
These early roles gave Alcock experience in television, presenting and scripted productions before her international breakthrough.
Early TV Career
From 2017 to 2020, Alcock appeared in Australian shows including Janet King, A Place to Call Home, Fighting Season, Pine Gap and Les Norton.
She also made her film debut in The School (2018), playing Jien.
By the end of this period, Alcock had become an established young Australian actor. Reporting has noted that she was still working part-time at a café in Sydney’s Marrickville right up until filming began on House of the Dragon.
Upright Breakthrough
A major step came with Upright, starring Tim Minchin. Alcock played Meg Adams, a runaway teenager traveling across Australia with Minchin’s character, Lucky Flynn.
The role allowed her to combine comedy and drama and earned her an AACTA Award nomination for Best Comedy Performer.
She returned for the second season in 2022, but her career had already moved toward international recognition.
House of the Dragon Breakthrough
Milly in House of the Dragon
In 2021, Alcock was cast as young Princess Rhaenyra Targaryen in HBO’s House of the Dragon, based on George R. R. Martin’s Fire & Blood.
Rhaenyra is a young royal facing conflict over succession, family, tradition and power. Alcock’s performance showed the character’s confidence, vulnerability and frustration.
Emma D’Arcy later played the older Rhaenyra as the story moved forward. Alcock’s performance became one of the most recognizable parts of the first season.
Why Rhaenyra Was a Breakthrough
House of the Dragon placed Alcock in one of television’s biggest fantasy franchises. The show’s connection to Game of Thrones brought worldwide attention.
Alcock made young Rhaenyra memorable through subtle expressions, reactions and emotional performances.
Her work earned a Critics Choice Television Award nomination for Best Supporting Actress in a Drama Series and made her an internationally recognized actor.
Why Did She Leave?
Alcock’s departure was mainly part of the show’s planned time jump. As Rhaenyra aged, Emma D’Arcy took over the role.
The change was part of the story’s structure rather than simply Alcock quitting the series.
Alcock later made a brief special appearance connected to Rhaenyra, while D’Arcy continued as the adult character.
What Did She Do Next?
After House of the Dragon, Alcock took on projects outside fantasy. In 2023, she made her West End debut as Abigail Williams in Arthur Miller’s The Crucible at London’s Gielgud Theatre.
She also appeared in Noel Gallagher’s High Flying Birds’ 2023 music video for “Easy Now.”
Later Career, Sirens and Supergirl
Milly in Sirens
In 2025, Alcock starred in Netflix’s limited series Sirens alongside Julianne Moore, Meghann Fahy and Kevin Bacon.
She played Simone DeWitt, a young woman working as the live-in personal assistant to wealthy socialite Michaela Kell, played by Moore.
The role was very different from Rhaenyra and allowed Alcock to explore dark comedy and contemporary drama.
How She Became Supergirl
In January 2024, Alcock was announced as Kara Zor-El/Supergirl in the new DC Universe.
Her first appearance as Kara came in Superman in 2025 in an uncredited appearance. She then took the lead role in Supergirl in 2026.
The role marked another major move from Australian television into a major global franchise.
Milly in Supergirl
Supergirl was released on June 26, 2026, directed by Craig Gillespie and written by Ana Nogueira, with Alcock in the title role. The film presents Kara as a tougher and more complicated version of the character.
Her story includes Krypto, Ruthye Marye Knoll and a revenge-driven interstellar journey, combining action, humor and emotional drama. The cast also features Matthias Schoenaerts as the mercenary Krem of the Yellow Hills, Eve Ridley as Ruthye, and Jason Momoa as Lobo.
The film received a mixed critical response, settling at around 52% on Rotten Tomatoes, although Alcock’s performance received positive attention from some critics and viewers. The Hollywood Reporter’s chief film critic called the film an “uninspired slog” while praising Alcock’s “hard-edged performance.”
The movie’s box office was weaker than its franchise ambitions. Published estimates put the budget at around $170 million to $180 million, with reported marketing costs of roughly $120 million, while worldwide theatrical revenue was approximately $126 million.
Because these figures can vary by source, they are best treated as estimates.
Supergirl Award Win
Despite the film’s commercial performance, Alcock won the Critics Choice Super Award for Best Actress in a Superhero Movie in 2026 for Supergirl.
She beat a competitive field that included Rachel Brosnahan (Lois Lane in Superman), Vanessa Kirby and Julia Garner (The Fantastic Four: First Steps), Camila Mendes (Masters of the Universe) and Adeline Rudolph (Mortal Kombat II). Her Superman co-star David Corenswet won Best Actor in a Superhero Movie at the same ceremony.
The award added an important achievement to a career that had already brought recognition for Upright and House of the Dragon.
It also shows that an actor’s performance can receive recognition separately from a film’s box-office results.
Rhaenyra vs. Supergirl
Rhaenyra Targaryen and Kara Zor-El are very different characters.
Rhaenyra is a royal heir dealing with political pressure, family conflict and her claim to the throne. Her story relies heavily on dialogue, relationships and subtle emotions.
Supergirl requires a different approach, with action, physical danger and a large-scale cosmic adventure.
Both characters, however, face expectations because of who they are. Alcock shows her range by approaching that shared conflict through very different genres.
Milly’s Acting Style
Alcock often uses facial expressions, physical presence and emotional shifts instead of relying only on dialogue.
This worked especially well in House of the Dragon, where Rhaenyra often had to hide or control her emotions.
In Sirens, she used a similar skill to show Simone’s confident exterior and deeper emotions. Supergirl required her to add action, humor, physical confidence and vulnerability.
Her ability to play characters who are not always easy to read has become an important part of her acting style.
Milly Alcock Movies and TV Shows
Alcock’s filmography is still relatively compact compared with many established actors, but it covers several formats.
Movies
| Year | Film | Role |
|---|---|---|
| 2018 | The School | Jien |
| 2025 | Superman | Kara Zor-El / Supergirl |
| 2026 | Supergirl | Kara Zor-El / Supergirl |
| Upcoming | Man of Tomorrow | Kara Zor-El / Supergirl |
| Upcoming | Thumb | Role not publicly detailed in the available sources |
| Upcoming | Untitled Takashi Miike project | Role not publicly detailed |
Television
| Year | TV show | Role |
|---|---|---|
| 2014 | Wonderland | Teen Girl 1 |
| 2015–2016 | B.F. Chefs | Presenter |
| 2017 | Hanging With | Presenter |
| 2017 | Janet King | Cindi Jackson |
| 2018 | A Place to Call Home | Emma Carvolth |
| 2018 | Fighting Season | Maya Nordenfelt |
| 2018 | Pine Gap | Marissa Campbell |
| 2019 | Les Norton | Sian Galese |
| 2019–2022 | Upright | Meg Adams |
| 2020 | The Gloaming | Jenny McGinty |
| 2020 | Reckoning | Sam Serrato |
| 2022–2024 | House of the Dragon | Young Rhaenyra Targaryen |
| 2025 | Sirens | Simone DeWitt |
Her web work includes High Life, in which she played Isabella Barrett in a six-episode miniseries. That credit belongs in the web category rather than being mixed into her television résumé.
Theatre and Music
In 2023, Alcock played Abigail Williams in The Crucible at London’s Gielgud Theatre, marking her West End debut.
She also appeared in Noel Gallagher’s High Flying Birds’ 2023 music video for “Easy Now.”
Milly Alcock Awards and Nominations
| Year | Award | Category | Result | Project |
|---|---|---|---|---|
| 2018 | Casting Guild of Australia | Rising Stars | Won | Television career |
| 2020 | AACTA Awards | Best Comedy Performer | Nominated | Upright |
| 2022 | IGN Summer Movie Awards | Best Performance in a TV Series | Nominated | House of the Dragon |
| 2023 | Critics Choice Television Awards | Best Supporting Actress in a Drama Series | Nominated | House of the Dragon |
| 2023 | Critics Choice Super Awards | Best Actress in a Science Fiction/Fantasy Series | Nominated | House of the Dragon |
| 2023 | Logie Awards | Most Outstanding Actress | Nominated | Upright |
| 2024 | Saturn Awards | Best Performance by a Younger Actor on a TV Series | Nominated | House of the Dragon |
| 2026 | Critics Choice Super Awards | Best Actress in a Superhero Movie | Won | Supergirl |
The progression from an Australian rising-star award to major international nominations and then a 2026 superhero award win provides a useful picture of how Alcock’s professional recognition has developed.
Milly Alcock Career Timeline
- 2000: Born in Sydney, Australia.
- 2014: Makes her credited television debut in Wonderland.
- 2015–2017: Works in Australian television and presenting, including B.F. Chefs and Hanging With.
- 2017: Appears in Janet King and the web miniseries High Life.
- 2018: Works on A Place to Call Home, Fighting Season, Pine Gap and The School.
- 2019: Stars as Meg Adams in Upright.
- 2020: Appears in The Gloaming and Reckoning.
- 2021: Is announced as young Rhaenyra Targaryen in House of the Dragon.
- 2022: House of the Dragon makes her internationally famous; she relocates to London.
- 2023: Makes her West End debut in The Crucible and appears in the “Easy Now” music video.
- 2024: Is announced as DC’s new Supergirl.
- 2025: Appears as Kara Zor-El/Supergirl in Superman and stars as Simone DeWitt in Netflix’s Sirens.
- 2026: Stars in Supergirl and wins the Critics Choice Super Award for Best Actress in a Superhero Movie.
Milly Alcock’s Personal Life
Alcock has generally kept her personal life private, choosing to keep attention on her acting career rather than discussing relationships, finances or other private matters publicly.
Before House of the Dragon brought her international fame, she lived and worked in Australia while building her acting career. She relocated to London in 2022 as her professional opportunities expanded.
Her move from Sydney to the United Kingdom reflects how much her career has grown. She has since worked across Australian television, British theatre, American television and major Hollywood productions.
Milly Alcock’s Career in 2026
A New Stage in Her Career
At 26, Milly Alcock is entering an important stage of her acting career. In just a few years, she has moved from Australian television to major international productions.
Her career now includes work in Australian TV, HBO fantasy, Netflix drama, West End theatre and DC superhero films. This gives her a much broader résumé than she had when she first became famous.
From Australia to Hollywood
Alcock started her career in Australia, appearing in television shows and smaller productions before gaining wider attention through Upright.
Her breakthrough came with House of the Dragon, where she played young Rhaenyra Targaryen. The role introduced her to a global audience and helped open the door to larger international opportunities.
Her move into the DC Universe with Supergirl shows how far her career has progressed in a relatively short time.
Moving Beyond Rhaenyra
One of the most important parts of Alcock’s career is her decision to take different types of roles.
After House of the Dragon, she did not simply look for another fantasy character. She appeared on the West End stage in The Crucible, starred in Netflix’s Sirens and then moved into superhero cinema.
These projects allowed her to show that she can play very different characters instead of being known only as Rhaenyra Targaryen.
What Supergirl Means for Her Career
Playing Supergirl is another major milestone because Kara Zor-El is one of DC’s most recognizable characters.
The role gives Alcock the chance to lead a major franchise rather than appear only as part of an ensemble cast. It also requires her to handle action, comedy and emotional scenes.
This could make Supergirl one of the defining roles of the next stage of her career.
Supergirl and Its Mixed Results
Supergirl created a mixed picture for Alcock’s career.
The film faced challenges at the box office, but its commercial performance does not necessarily reflect Alcock’s individual work. She received recognition for her performance, including the Critics Choice Super Award for Best Actress in a Superhero Movie.
The contrast is important because a film can struggle commercially while an individual actor still receives praise and career recognition.
What Comes Next for Milly Alcock?
Her next major expected project is Man of Tomorrow, in which she is set to reprise her role as Kara Zor-El/Supergirl.
Returning to the character could allow Alcock to develop Kara further and explore sides of the superhero that were not fully covered in the first film.
Why 2026 Is Important
The year 2026 represents an important point in Alcock’s career because she is no longer simply the young Australian actor who became famous through House of the Dragon.
She has now worked across several major entertainment industries and has demonstrated that she is willing to take on very different roles.
If Man of Tomorrow gives her another strong opportunity as Supergirl, it could further establish Alcock as one of the leading young actors in major international film and television.
What Are Milly Alcock’s Upcoming Movies?
The most significant announced project is Man of Tomorrow, in which Alcock is expected to return as Supergirl.
She has also been linked to Thumb, a dark comedy project associated with Sofia Vergara, and an untitled project from Japanese director Takashi Miike.
Because film projects can change during development or production, announced titles should not automatically be treated as confirmed release dates. For now, Man of Tomorrow is the clearest continuation of Alcock’s current franchise career.
What Makes Milly Alcock’s Career Different?
Alcock’s career stands out because her success did not come from a single role or genre. She began in Australian television, developed her skills through projects such as Upright, gained international recognition in House of the Dragon, and then moved into theatre, contemporary drama and superhero filmmaking.
Her career can be summarized as:
Australian television → Upright → House of the Dragon → West End → Sirens → DC’s Supergirl.
Each stage has required a different performance style, making her career particularly interesting as she moves into her next phase.
Conclusion
Milly Alcock’s career is about more than one breakout role. Although House of the Dragon introduced her to a global audience as young Rhaenyra Targaryen, her success was built through years of Australian television work and the acclaimed Upright. Since then, she has continued to challenge herself through West End theatre, Netflix’s Sirens and DC’s Supergirl.
In 2026, Alcock has reached a new stage as Kara Zor-El/Supergirl. While Supergirl underperformed at the box office, her performance earned the Critics Choice Super Award for Best Actress in a Superhero Movie. Her expected return in Man of Tomorrow gives her another opportunity to develop the character and strengthen her place in the DC Universe.
What makes Alcock’s future especially interesting is her versatility. She has already moved successfully between television drama, fantasy, comedy, theatre and blockbuster filmmaking. Whether Supergirl becomes her defining franchise role or simply another milestone, her career is clearly still evolving.
Frequently Asked Questions About Milly Alcock
1. How old is Milly Alcock?
Milly Alcock was born on April 11, 2000, so she is 26 years old in 2026.
2. What is Milly Alcock famous for?
She is best known internationally for playing young Rhaenyra Targaryen in HBO’s House of the Dragon and Kara Zor-El/Supergirl in the DC Universe.
3. Who did Milly Alcock play in House of the Dragon?
She played young Princess Rhaenyra Targaryen during the first season. Emma D’Arcy later played the adult version of the character following the show’s major time jump.
4. Why did Milly Alcock leave House of the Dragon?
Her main role ended because the story jumped forward in time and required an older Rhaenyra, who was played by Emma D’Arcy. Alcock later appeared in a smaller capacity in the second season.
5. Who does Milly Alcock play in Supergirl?
She plays Kara Zor-El, also known as Supergirl, in DC Studios’ Supergirl. She first appeared as the character in Superman before leading her own film.
6. Did Milly Alcock appear in Superman?
Yes. Alcock appeared as Kara Zor-El/Supergirl in Superman in 2025, ahead of her starring role in Supergirl.
7. What movies and TV shows has Milly Alcock been in?
Her credits include The School, Superman, Supergirl, Upright, House of the Dragon, Sirens, Pine Gap, Fighting Season, A Place to Call Home, The Gloaming and Reckoning. Her work also includes theatre and web productions.
8. Has Milly Alcock won any acting awards?
Yes. Among her recognitions, she won a 2026 Critics Choice Super Award for Best Actress in a Superhero Movie for Supergirl. She had previously received nominations for work in Upright and House of the Dragon.
9. What is Milly Alcock’s next movie?
One of her major upcoming projects is Man of Tomorrow, where she is expected to return as Supergirl. The film is part of the continuing DC Universe.
10. Where is Milly Alcock from?
Milly Alcock is from Sydney, New South Wales, Australia. She grew up in Sydney before her acting career eventually took her to international productions.
11. What role did Milly Alcock play in Sirens?
She played Simone DeWitt, the younger sister of Devon and the personal assistant to Julianne Moore’s character, Michaela Kell. Netflix describes the series as a dark comedy exploring relationships, wealth, power and class.
12. Did Milly Alcock work before House of the Dragon?
Yes. She had been working professionally for years before House of the Dragon. Her earlier credits include Wonderland, Janet King, A Place to Call Home, Fighting Season, Pine Gap, Les Norton and Upright.
