Mary Elizabeth Winstead was born on November 28, 1984, in Rocky Mount, North Carolina, and is the youngest of five children. Her family moved to Sandy, Utah, when she was five years old, where she attended Peruvian Park Elementary and took advanced classes.

She discovered a love for the performing arts at a young age and began training to be a ballerina, attending the Joffrey Ballet School training program at the age of 12. Around this time, she also started pursuing a career in acting and soon began working steadily in television and film.

Her first major role was that of Jessica Bennett on the NBC soap opera "Passions" from 1999 to 2000. She came to wider attention for her roles in the horror series "Wolf Lake" (2001-2002), the horror films "Final Destination 3" (2006) and "Death Proof" (2007), and the slasher film "Black Christmas" (2006).

By the end of the 2000s, she had gained a reputation as a scream queen. Further success came with her roles as John McClane's daughter in "Live Free or Die Hard" (2007) and Ramona Flowers in "Scott Pilgrim vs. the World" (2010). Her critically acclaimed performance as an alcoholic struggling with sobriety in the drama "Smashed" (2012) was followed by a series of roles in other independent films, including "The Beauty Inside" (2012), "The Spectacular Now" (2013), "Faults" (2014), "Alex of Venice" (2014), and "Swiss Army Man" (2016).

In addition to her acting career, she is also a recording artist and performs as part of the music duo "Got a Girl" with producer Dan the Automator since 2013. She returned to television with the drama series "The Returned" (2015), the comedy series "BrainDead" (2016), the medical drama series "Mercy Street" (2016-2017), and the third season of the crime drama "Fargo" (2017).

Her other roles include the comedy-drama "All About Nina" (2018), the action film "Gemini Man" (2019), the Huntress in "Birds of Prey" (2020), and Hera Syndulla in the Star Wars series "Ahsoka" (2023).

Her personal life includes her marriage to filmmaker Riley Stearns in 2010, which ended in divorce in 2017. She married actor Ewan McGregor in 2022, and the couple welcomed their first child, Laurie McGregor, in June 2021.

Throughout her career, she has received several awards and nominations, including an Independent Spirit Award nomination for her role in "Smashed" and a Saturn Award for her performance in "10 Cloverfield Lane."