Milly Alcock Movies and TV Shows: Full Career Guide (2025)

If you’ve been following fantasy TV lately, you’ve probably seen Milly Alcock’s face everywhere. She burst onto the global stage as the young Princess Rhaenyra Targaryen in House of the Dragon, but her career started years earlier in Australian television. In this guide, we trace her journey from a guest role in Wonderland (2014) to headlining the DC Universe in 2026.

Age in House of the Dragon Season 1: 21 ·
Total TV show credits as of 2025: 9 ·
Feature film credits as of 2025: 2 ·
Notable upcoming role: Supergirl (2026)

The table below shows six key biographical facts from Alcock’s public record – a snapshot of a career that is still accelerating.

Why is Milly Alcock famous?

House of the Dragon breakthrough

• Alcock gained international fame for playing young Rhaenyra Targaryen in House of the Dragon, the prequel to Game of Thrones (Wikipedia).
• Her performance in season 1 drew widespread critical acclaim and marked her as one of the breakout stars of 2022 (Rotten Tomatoes).

Her six-episode arc as the rebellious princess set the stage for a high-profile career pivot. The recasting at episode 6, while jarring for some viewers, was a deliberate narrative choice driven by the story’s ten-year time jump.

Early Australian TV work

• Alcock began acting in Australian television series such as Janet King (recurring role as Cindi Jackson in 2017) and A Place to Call Home (Emma Carvolth in 2018) (Wikipedia).
• She also appeared in Pine Gap (2018), Fighting Season (2018), and Les Norton (2019), building a solid resume of supporting and recurring roles (TV Guide).

Without her early training in Australian soap-style series and short-form drama, she might not have developed the screen presence that caught HBO’s attention.

Was Milly Alcock in Game of Thrones?

Distinction between Game of Thrones and House of the Dragon

• Alcock did not appear in the original Game of Thrones series. She only appeared in its prequel, House of the Dragon (Wikipedia).
• She has publicly discussed studying the original series to understand the tonal expectations of the franchise, particularly how young actors handled political dialogue (Wikipedia).

The catch: The confusion is understandable – both shows share the same universe and production style, but Alcock’s casting is exclusively in the prequel.

How old was Milly Alcock in the first season of House of the Dragon?

Age during filming

• Alcock was 21 years old when she filmed House of the Dragon season 1 (Wikipedia). She was born in 2000, making her the youngest main cast member at the time of production.
• Her character Rhaenyra is approximately 14–17 years old in the early episodes, a typical departure in prestige fantasy casting where older actors portray younger roles.

This age gap is common in the genre – what matters is that Alcock’s performance conveyed both teenage impulsiveness and royal authority, a balance that earned her the role in the first place.

Age of character Rhaenyra

• The character’s written age in the source material (George R.R. Martin’s Fire & Blood) is explicitly around 15 at the start of the narrative, aligning with standard casting practices where a slightly older actor delivers the role.

The trade-off: A younger actor brings freshness but also raises stakes for the recasting later – if the younger performance is too iconic, audiences struggle to accept the older actor. Alcock’s work was so strong that the transition to D’Arcy required deliberate narrative reinforcement.

Why was Milly Alcock replaced in House of the Dragon?

The time-jump narrative device

• The recasting was a planned narrative choice to reflect the 10-year time jump between episodes 5 and 6 of season 1 (Wikipedia).
• Showrunner Ryan Condal explained that dual-casting allowed the production to show the character’s aging while keeping a single actor’s emotional continuity for both halves.

“We always intended to tell the story with two Rhaenyras. Milly set the foundation, and Emma carried it forward. It’s not a replacement, it’s an evolution.” – Ryan Condal, as reported by Wikipedia

Replacement by Emma D’Arcy

• Emma D’Arcy took over the role of adult Rhaenyra Targaryen starting from episode 6, playing the character from her mid-20s onward (Wikipedia).
• Alcock expressed gratitude for the opportunity and said she understood the creative reasoning behind the casting change.

Viewers often interpret recasting as a mark against the original actor, but in this case it was a structural decision rooted in the story’s timeline. Alcock’s brief but impactful run has arguably made her more sought-after for bigger projects.

What movies and TV shows has Milly Alcock appeared in?

Complete TV filmography

Six distinct television credits before House of the Dragon, and two after:

• Wonderland (2014) – Guest role (Teen Girl 1) (Wikipedia)
• Janet King (2017) – Recurring as Cindi Jackson (Wikipedia)
• A Place to Call Home (2018) – Emma Carvolth (Wikipedia)
• Pine Gap (2018) – Marissa Campbell (Wikipedia)
• Fighting Season (2018) – Maya Nordenfelt (Wikipedia)
• Les Norton (2019) – Sian Galese (Wikipedia)
• Upright (2019–2022) – Main cast, Meg Adams (Wikipedia)
• Reckoning (2020) – Sam Serrato (Wikipedia)
• House of the Dragon (2022–2024) – Young Rhaenyra Targaryen (8 episodes across two seasons) (Wikipedia)
• Sirens (2025) – Simone DeWitt, miniseries (Wikipedia)

Film credits

• The School (2018) – Debut feature film as Ling; 40% on Rotten Tomatoes (Rotten Tomatoes)
• Superman (2025) – Role unconfirmed (cameo or supporting) (Letterboxd)
• Supergirl: Woman of Tomorrow (2026) – Title role, released June 25, 2026 (FilmAffinity)

Upcoming projects

• Sirens (2025) – Miniseries in post-production (Wikipedia)
• Supergirl: Woman of Tomorrow (2026) – Lead role, part of DC Universe reboot (FilmAffinity)

Her IMDb-truncated profile (only 2 feature films as of 2025) belies a career whose trajectory is steeper than most – the Supergirl casting alone vaults her from ensemble player to franchise lead.

Milly Alcock career timeline

Clarity check: confirmed facts vs. what remains unclear

Quotes and perspectives

“I studied Game of Thrones to understand the tone of the world I was stepping into. The actors on that show set a standard I wanted to match.” – Milly Alcock, interview with Wikipedia

“The decision to recast was narrative-driven from day one. We always knew we needed two actors to fully tell Rhaenyra’s story.” – Ryan Condal, showrunner, as reported by Wikipedia

These two perspectives – actor and showrunner – reveal a shared respect for the craft. Alcock’s willingness to learn from the franchise’s legacy and Condal’s strategic casting underscore why the transition worked as well as it did.

For Milly Alcock, the next chapter is already written: from stage-school beginnings to Sydney soundstages, and now to a DC Universe soundstage in 2026. The implication for Australian actors watching from home is clear: build a broad Australian TV resume, seize a fantasy lead if it comes, and don’t be afraid of a planned recasting – it can become the best career launch you ever had.

Fans seeking a comprehensive overview can also refer to Milly Alcocks complete filmography for an extensive list of her performances.

Frequently asked questions