Milly Alcock: Rising Star Takes on Supergirl and Beyond

Introduction: A Rising Force in Hollywood

Australian actress Milly Alcock has emerged as one of Hollywood’s most exciting young talents, capturing global attention with her powerful performances across television and film. Best known for her breakout role as young Rhaenyra Targaryen in HBO’s House of the Dragon, the 25-year-old Sydney native is now poised to become a cornerstone of the DC Universe as Supergirl. Her journey from Australian television to major franchise stardom represents a remarkable career trajectory that continues to accelerate in 2025.

Alcock’s significance extends beyond her impressive resume. She represents a new generation of performers who bring depth, authenticity, and versatility to both prestige television and blockbuster cinema. Her ability to navigate between intimate character studies and large-scale superhero productions demonstrates the range that has made her one of the industry’s most sought-after talents.

Netflix Success with Sirens

Alcock’s dark comedy limited series Sirens premiered on Netflix on May 22, 2025, showcasing her dramatic range alongside industry veterans Julianne Moore, Meghann Fahy, and Kevin Bacon. In the series, Alcock plays Simone DeWitt, a sharp and charming younger sister working as a personal assistant to a billionaire. The show explores themes of power, class, and family dynamics against the backdrop of a luxurious beach estate.

According to data from Showlabs, Sirens ranked first on Netflix in the United States during the week of 19-25 May 2025, receiving generally favorable reviews from critics. Critics particularly praised Alcock’s performance, with Rotten Tomatoes’ critical consensus noting ‘laudable performances by Julianne Moore, Meghann Fahy, and Milly Alcock’.

DC Universe’s New Supergirl

The biggest milestone in Alcock’s career came with her casting as Kara Zor-El in the DC Universe. In January 2024, it was announced that Alcock had been cast to play Supergirl in the DC Universe film Supergirl (2026), first making a cameo appearance as the character in Superman (2025). Production on ‘Supergirl: Woman of Tomorrow’ began in January 2025, with star Milly Alcock and DC Studios co-chief James Gunn sharing the first image from the set.

Early reactions to Alcock’s performance have been overwhelmingly positive. Test screening leaker ViewerAnon stated: ‘Milly Alcock is FANTASTIC, like Robert Downey Jr/Chris Evans You-Can-Build-a-Whole-Universe-Around-Her great’. However, Alcock herself initially struggled with the magnitude of the role. The actress admitted, ‘I thought, What have I done? I really struggled to believe I could do it. I even called the director, saying, I don’t know how to be that person’.

Future Projects and Industry Impact

House of the Dragon and Supergirl actor Milly Alcock will star in Daina Oniunas-Pusić’s dark comedy Thumb, which follows a lonely woman who mistakenly receives a severed thumb in the mail. Cameras roll this fall in New York, adding another compelling project to her expanding filmography.

Conclusion: A Star on the Ascent

Milly Alcock’s rapid ascent from Australian television to global stardom demonstrates both her exceptional talent and the industry’s recognition of her potential. With Sirens earning critical acclaim and Supergirl: Woman of Tomorrow set to release on June 26, 2026, Alcock stands at the threshold of true superstardom. Her willingness to embrace challenging roles while maintaining authenticity positions her as more than just another franchise player—she represents the future of Hollywood storytelling.

For audiences and industry observers alike, Milly Alcock’s career trajectory offers a compelling narrative of talent, determination, and the transformative power of authentic performance. As she prepares to don Supergirl’s cape, the entertainment world watches with anticipation to see how this remarkable young actress will continue to redefine what it means to be a modern film star.