Browning was born in Melbourne, Victoria, the daughter of Andrew and Shelley Browning. She attended Hurstbridge Learning Co-op and Eltham High School. Browning has two younger brothers, Nicholas and Matthew.
Browning's debut acting role was in the 1998 Hallmark Channel movie The Echo of Thunder. Additional roles in Australian film and television productions soon followed, including recurring roles in the television series Blue Heelers from 2000 to 2002, and Something in the Air from 2000 to 2001. In 2001, Browning appeared as the daughter of a character played by Billy Connolly in The Man Who Sued God.
She made her American film debut in 2002's Ghost Ship, and won an Australian Film Institute Award for Best Young Actress, the same year. In 2003, she appeared opposite Heath Ledger and Orlando Bloom in 2003's Ned Kelly, and then reunited with Connolly the following year in the film adaptation of Lemony Snicket's A Series of Unfortunate Events, in which she played Violet Baudelaire.
In 2006, Browning appeared in the music video for Evermore's "Light Surrounding You". In the behind-the-scenes video for the clip, the band stated, "[We] suck as actors, so we decided to get Emily." She attended the L'Oreal Fashion Festival as a festival ambassador on 1 February 2007.
Browning played the lead role in the 2009 horror film The Uninvited, an American remake of the 2003 South Korean film A Tale of Two Sisters, co-starring alongside Elizabeth Banks and Arielle Kebbel. She then turned down a request to audition for the role of Bella Swan in Twilight, citing exhaustion, despite an endorsement from series author Stephenie Meyer. In 2009, she was cast as Babydoll in Zack Snyder's action film Sucker Punch, as a replacement for Amanda Seyfried, who dropped out due to scheduling conflicts. Filming took place in Vancouver from September 2009 to January 2010, and the film was released on 25 March 2011. In an interview at Comic-Con, she confirmed that she would be singing in the film, while claiming that her audition tape brought tears to her casting agent's eyes and the song she selected ("Killing Me Softly") was one of Zack Snyder's wife Deborah's favourites, which Browning referred to as the "selling point" on her being cast in the role.
Since Sucker Punch, Browning has worked steadily in film. In February 2010, it was announced that Browning would play the lead role in the independent Australian film Sleeping Beauty, directed by Julia Leigh. She replaced friend and fellow young Australian actress Mia Wasikowska, who was committed to a film adaptation of Jane Eyre at the time. The film screened at the 2011 Cannes Film Festival and the Sydney Film Festival. In a review from the festival, Peter Bradshaw of The Guardian called the film "Technically elegant with vehemence and control ... Emily Browning gives a fierce and powerful performance ... There is force and originality in Leigh's work". Fionnuala Halligan in Screen International wrote "Browning has gone the distance for her director and together, they have delivered something here that sometimes catches your breath". At the festival Browning said, "Even reading the screenplay, it made me feel uncomfortable. But that was something that attracted me to it. I would prefer to polarise an audience as opposed to making an entertaining film everybody feels ambivalent about."
In 2012, she replaced English actress Ophelia Lovibond as the female lead in the film Summer in February. The film is based on the book of the same title, by Jonathan Smith. The film was filmed in Cornwall alongside Dominic Cooper and Dan Stevens. In July 2012, Browning was cast in God Help the Girl, a musical film by Belle and Sebastian front-man Stuart Murdoch. Browning played Eve, and the role required live singing. Filming on the production began on 8 July 2012 and wrapped on 12 August 2012.
Browning was then cast in Catherine Hardwicke's Plush alongside Cam Gigandet, replacing Evan Rachel Wood (who was originally attached to the project) due to scheduling conflicts. Browning also starred alongside Xavier Samuel whom she met on the set during filming. Magic Magic, directed by Sebastián Silva, screened at the 2013 Sundance Film Festival. Film.com designated the film as a "Top Pick".
Browning starred in the 2014 film Pompeii, opposite Kit Harington, best known for Game of Thrones. The project was filmed in Toronto and the actual city of Pompeii itself. Browning took a break from filming on Pompeii, and returned home to Australia to film a music video directed by Guy Franklin for the song "No Matter What You Say" by the San Francisco-based band Imperial Teen. The video follows Browning as the lead character, conducting a 'live art-piece'.
In 2014, Browning filmed Shangri-La Suite, directed by Eddie O'Keefe. The story follows two young lovers who break out of a mental hospital in 1974 and set out on a road trip to Los Angeles to fulfill the boy's lifelong dream of killing his idol Elvis Presley, who appears as a supporting character. Luke Grimes and Avan Jogia co-star. The same year, she appeared in Years & Years's Take Shelter music video.
In 2015, Browning starred in the biopic crime thriller movie Legend, alongside Tom Hardy, who portrayed twin brothers Reggie and Ronnie Kray. She portrayed Frances Shea, the first wife of Reggie Kray.
Browning was cast in American Gods as Laura Moon. Neil Gaiman, author of the novel, said, "I've been fascinated by Emily Browning since A Series of Unfortunate Events. She has a challenge ahead of her: Laura is a tricky character, and the Laura on the screen is even trickier and more dangerous than the one on the page. She's going to have a wonderful time bringing Laura to life".