Considered to be one of the finest actors of her generation, Hailee Steinfeld was born on 11 December 1996 in Tarzana, California, to Cheri (née Domasin), an interior designer, and Peter Steinfeld, a personal fitness trainer, who also occasionally acted on television. Initially raised in Agoura Hills, a city situated in the Santa Monica Mountains of Los Angeles County, and later in Thousand Oaks, the second-largest city in Ventura County, located in the southern part of California, she attended Ascension Lutheran School, Conejo Elementary, before becoming completely homeschooled from 2008 until her high school graduation in June 2015. However, inspired by her elder cousin appearing in a commercial, she wished to pursue acting when she was only eight, and although she wanted to start auditioning for the purpose immediately, she was insisted by her mother to attend acting classes to learn skills and prove the seriousness of her desire for a career in show business. After a year of training, Hailee Steinfeld began acting at age 10, appearing in several commercials which included the clothing company Gap Inc, her first television appearance in an episode of Back to You (2007), and then an angel in the short film Heather: A Fairy Tale (2008), after which she got the opportunity to play the role of Talia Alden, a dream girl worthy of sacrificing a beloved mullet in another short film, She’s a Fox (2009), which won several awards.

However, Hailee Steinfeld earned overnight stardom, when after beating out thousands of other hopeful young actresses, she landed her first feature film role in True Grit (2010), playing Mattie Ross, the strong-willed frontier girl who hired ageing marshal Rooster Cogburn to avenge her father's death. She stunned the critics with her charismatic poise and confident performance in the film, and was nominated for an Academy Award for Best Performance by an Actress in a Supporting Role. Five months after the release of the film, Hailee was chosen to be the new face of the famous Italian fashion designer for women, Miu Miu, a fully owned subsidiary of Prada.

After some time away from her screen work, Hailee Steinfeld returned in 2013 with a number of projects, including the romantic drama film Begin Again (2013), in which she played the role of Violet, followed by the role of Sabitha, a recovering addict in Hateship Loveship (2013), portrayed the key character of Petra Arkanian in the science fiction adventure Ender's Game (2013), based on the Orson Scott Card novel and starring Asa Butterfield and Harrison Ford, along with the short film The Magic Bracelet (2013). Apart from that, she also starred as Juliet opposite fellow actor-on-the-rise Douglas Booth in a feature adaptation of William Shakespeare's perennially performed romantic tragedy Romeo & Juliet (2013). Interestingly, the role of Juliet was originally intended for a 22-year-old actress, as there was concern about nudity in the film, but when Hailee was cast to portray the role, the script was changed to make it age-appropriate, without nudity. However, the film earned poor reviews on its release in the United States and internationally.

The next year, Hailee appeared in the major role of Zooey Renner, daughter of a dying CIA Agent, Ethan Renner, played by Kevin Costner, in 3 Days to Kill (2014), followed by the role of Tabitha Hutchinson in Tommy Lee Jones' western The Homesman (2014), and the role of Louise, one of the three desperate Southern women in the waning days of the American Civil War, in Daniel Barber’s thriller The Keeping Room (2014). In 2015, Steinfeld joined the cast of Pitch Perfect 2 (2015), performing the role of Emily Junk, an earnest fresh girl trying to establish herself in a competitive all-female singing group, played the role of Megan Walsh, an assassin who tries to live a normal life as a high school student, in the action comedy Barely Lethal (2015), co-starring Jessica Alba, and also appeared as Eliza, opposite Asa Butterfield, in the musical drama Ten Thousand Saints (2015).

Throughout her career, Hailee Steinfeld has constantly proved her worth and has impressed her fans with her skills and talent. In 2016, she starred in the teen romantic comedy The Edge of Seventeen (2016), playing the role of Nadine, a high-school girl, whose life gets even more unbearable, when her older brother starts dating her best friend, Krista. For her performance in the role, she received a Golden Globe nomination for Best Actress in a Motion Picture-Comedy or Musical, along with a Critics Choice Award nomination for Best Young Actress.

The next year, she again appeared as Emily Junk in Pitch Perfect 3 (2017), reprising her role in the previous instalment, followed by the role of Charlie, in the big-budget science fiction action film Bumblebee (2018), based on the Transformers toy line character. Her subsequent important films include Charlie’s Angels (2019), in which she appeared in a cameo role as an Angel Recruit, and the supernatural horror film Sinners (2025), in which her character engages in some very intimate and vulnerable scenes with co-star Michael B. Jordan that made waves in the media, praising her range. However, apart from appearing on the screen as an actress, Hailee Steinfeld also lent her voice to several films and series, most notably voicing for Gwen Stacy in Spider-Man: Across the Spider-Verse (2023), the Spider-Verse animated film saga, and for Vi in the Netflix series Arcane. (2021-2024).

In addition to her career as a celebrated actress, Hailee Steinfeld is a versatile pop vocal artist, has a number of catchy songs, and hits like Starving and Most Girls, including a song titled "Flashlight" for the film Pitch Perfect 2, which led to the release of her debut single, Love Myself. She also made public appearances during several charity events, such as the Breast Cancer Foundation's 2014 Hot Pink Party. However, her music career has been perceived only as a side project due to its inconsistent output, which has prevented her from reaching the top tier of pop stardom.

In her personal life, Hailee Steinfeld dated the Instagram personality Cameron Smolle for a short period in 2017, and also had a public relationship with the Irish singer Niall Horan, before dating Josh Allen, quarterback of Buffalo Bills, a professional American football team, in May 2023. Finally, the couple got engaged in November 2024, and they were married in a private California ceremony on 31 May 2025, when the guests were asked to keep their phones away during the event.