Hilary Ann Swank (born July 30, 1974) is an American actress and film producer. She first became known in 1992 for her role on the television series Camp Wilder and made her film debut with a minor role in Buffy the Vampire Slayer (1992). Swank came to international recognition for her performances as Brandon Teena in Kimberly Peirce's Boys Don't Cry (1999) and as Maggie Fitzgerald in Clint Eastwood's Million Dollar Baby (2004). Both performances earned her widespread critical acclaim and numerous accolades, including two Academy Awards for Best Actress and two Golden Globe Awards for Best Actress in a Motion Picture – Drama. She was named by Time as one of the 100 most influential people in the world in 2005.

Swank later ventured into producing with the films Amelia (2009), Conviction (2010), You're Not You (2014), and What They Had (2018), in all of which she also starred. Other notable appearances include as Carly Reynolds on the eighth season of Beverly Hills, 90210 (1997–98), the television film Iron Jawed Angels (2004), and the feature films The Next Karate Kid (1994), The Black Dahlia (2006), Freedom Writers (2007), The Resident (2011), The Homesman (2014), Logan Lucky (2017), The Hunt (2020), and Fatale (2020). In 2022, she starred in the television drama series Alaska Daily.

Hilary Ann Swank was born on July 30, 1974, in Lincoln, Nebraska, to Judy Kay (née Clough) and Stephen Swank. Many of Swank's family members are from Ringgold County, Iowa. Her maternal grandmother, Frances Martha Clough (née Domínguez), was born in El Centro, California, and was of Mexican descent. Swank's paternal grandmother was born in England; her other ancestry includes Dutch, German, Ulster-Scots, Scottish, Swiss, and Welsh. The surname "Swank", originally "Schwenk", is of German origin.

After living in Spokane, Washington, Swank's family moved into a home near Lake Samish, near Bellingham, Washington, when Swank was six. She attended Happy Valley Elementary School, Fairhaven Middle School, then Sehome High School in Bellingham until she was 16. She competed in the Junior Olympics, the Washington state championships in swimming, and ranked fifth in the state in all-around gymnastics. Swank made her first appearance on stage when she was nine years old, starring in The Jungle Book.

When Swank was 15, her parents separated, and her mother, supportive of her daughter's desire to act, moved with her to Los Angeles, where they lived in their car until her mother saved enough money to rent an apartment. Swank has called her mother the inspiration for her acting career and her life. In California, Swank enrolled in South Pasadena High School, later dropping out. She described her time at that school: "I felt like such an outsider. I didn't feel like I fit in. I didn't belong in any way. I didn't even feel like the teachers wanted me there. I just felt like I wasn't seen or understood." She explained that she became an actor because she felt like an outsider, "As a kid I felt that I belonged only when I read a book or saw a movie, and could get involved with a character. It was natural that I became an actor because I longed so much to be those other people, or at least to play them."

Swank made her film debut in the 1992 comedy horror film Buffy the Vampire Slayer, playing a supporting role, after which she acted in the direct-to-video drama Quiet Days in Hollywood, where she co-starred with Chad Lowe, to whom she was married from 1997 to 2007.

Her first leading film role was in the fourth installment of the Karate Kid series, The Next Karate Kid (1994) as Julie Pierce. The role used her gymnastics background and paired her with Pat Morita. In 1994, she also starred in the drama, Cries Unheard: The Donna Yaklich Story, as the abused stepdaughter who was protected by Donna (Jaclyn Smith). In 1995, she appeared with British actor Bruce Payne in Kounterfeit. In 1996, she starred in a TV movie, family drama Terror in the Family, as a troubled teenager. In September 1997, Swank played single mother Carly Reynolds in Beverly Hills, 90210 and was initially promised it would be a two-year role, but saw her character written out after 16 episodes in January 1998. Swank later stated that she was devastated at being cut from the show, thinking, "If I'm not good enough for 90210, I'm not good enough for anything."

Being cut from Beverly Hills, 90210 freed her to audition for the role of Brandon Teena in Boys Don't Cry. To prepare for the role, Swank lived as a man for a month and reduced her body fat to 7%. She earned only $75 per day for her work on the film, culminating in a total of $3,000. Her earnings were so low that she had not even earned enough to qualify for health insurance. Upon release, many critics lauded her performance, with Premiere listing it as one of the "100 Greatest Performances of All Time". James Berardinelli wrote at the time that Swank "gives the performance of her career". Her work earned her several accolades, including the Golden Globe and Academy Award for Best Actress. In an interview with Variety in 2020, Swank said that she felt a trans actor should have played the role, and had she been offered it today, she would have refused it, stating "Twenty-one years later, not only are trans people having their lives and living, thankfully, although we still have a long way to go in their safety and their inclusivity, but we now have a bunch of trans actors who would obviously be a lot more right for the role and have the opportunity to actually audition for the role."