Sydney Sweeney unrecognisable after dramatic transformation for Christy Martin biopic at TIFF 2025

Highlights:

• Sydney Sweeney debuts first look as legendary boxer Christy Martin
• Biopic Christy to premiere at Toronto International Film Festival in September 2025
• Sweeney gained 30 pounds and trained intensely for the role
• Directed by David Michôd, film explores Christy Martin’s rise and survival story

Hollywood star Sydney Sweeney looks completely unrecognisable in the first official still from her upcoming film Christy, a biopic about American boxing icon Christy Martin. Known for her roles in Euphoria and The White Lotus, Sweeney steps into the ring with a dramatic physical and emotional transformation that has already sparked intense buzz ahead of its September premiere at the 2025 Toronto International Film Festival (TIFF).

Sydney Sweeney stuns with unrecognisable look as boxer Christy Martin Instagram/sydney_sweeney

What is Christy about?

The film follows the remarkable life of Christy Martin, one of the most influential figures in women’s boxing. Rising from a small town in West Virginia to national fame in the 1990s, Christy helped put women’s boxing on the map. She recorded 49 professional wins, 32 by knockout, and became the first woman signed by boxing promoter Don King.

But Martin’s career wasn’t the only part of her life that made headlines. Behind the scenes, she endured years of abuse from her trainer and husband, James Martin, who later tried to kill her. She survived a violent attack in 2010 in which he stabbed and shot her. The film not only charts her sporting achievements but also her fight for survival and her identity as a gay woman in a hyper-masculine sport.

Boxer Christy Martin from the United States bleeds from the nose during the WBC Championship Boxing Lightweight fight against Deirdre Gogarty of Ireland on 16th March 1996Getty Images

How did Sydney Sweeney prepare for the role?

In a June 2025 interview, Sweeney revealed she underwent an intense body transformation, gaining over 30 pounds and committing to a gruelling fitness routine. “I weight-trained in the morning, did two hours of kickboxing midday, and another session at night,” she said. “My body changed completely. I felt powerful.”

Fans first caught a glimpse of her transformation in October 2024 when she shared behind-the-scenes images from her training sessions. But the newly released official photo from Black Bear Pictures shows the full extent of her commitment. Gone are her signature blonde waves, replaced with Christy’s dark curls, boxing gloves, and a steely focus in the ring.

Fans react to Sydney Sweeney’s intense new look in boxing dramaGetty Images

Why this role is different for Sweeney?

Sweeney is known for playing emotionally vulnerable, glamorised characters. With Christy, she takes on a more grounded and gritty role, one that trades red carpets for leather gloves and blood-stained boxing rings.

Director David Michôd (The King) praised her dedication, saying he was stunned when he saw her again on the set of Euphoria season 3. “She was happiest when she was in the ring, getting hit and hitting back,” he said. “Seeing her switch back to Cassie, all glam and soft, was like witnessing two different people.”

From red carpets to boxing rings Sydney Sweeney sheds her glam image Getty Images

What has Christy Martin said about the biopic?

Martin, now 56 and a boxing promoter, has voiced her full support for the film and Sweeney’s casting. “I think she’s young, talented, and hot,” Martin said. “This movie is one fathers will watch with their daughters to talk about domestic violence.”

Martin now lives with her wife, Lisa Holewyne, and continues to work in boxing. She sees the film as more than just a tribute to her past—it’s a message of survival, identity, and strength.