Pataky was born in Madrid, Spain, the daughter of José Francisco Lafuente, a Spanish biochemist and Cristina Pataky Medianu, a publicist of Hungarian and Romanian ancestry. Pataky attended the Universidad de San Pablo CEU and studied journalism. During this time, Pataky also enrolled in acting classes.
As of December 28, 2010, Elsa is married to Chris Hemsworth. They made their relationship public at the opening Gala and "Unmasking" for the Resnick Pavilion at LACMA in Los Angeles September 25, 2010.
Pataky was a member of the Madrid theatre company, Teatro Cámara de Ángel Gutiérrez. Eventually, she left school when she was cast in the television series Al salir de clase. With the success of Al Salir de Clase, Pataky received her first film offer, El arte de morir. Some of her subsequent films were co-productions with the UK and France, which introduced her to working in English and French.
Pataky starred in the television series Queen of Swords (2000) as Señora Vera Hidalgo, trophy wife of Gaspar Hidalgo and mistress of Captain Grisham appearing in nearly all twenty-two episodes.
Pataky has appeared in over ten Spanish films and most recently crossed over into the French market with her co-starring role in the 2004 box office hit, Iznogoud. She also on the cover the August 2006 issue of Maxim due to her supporting role in the David Ellis-directed film Snakes on a Plane (2006), alongside Samuel L. Jackson. She received good reviews for her work in the Spanish film Ninette, helmed by Oscar winner José Luis Garci. She participated in 2009 in the Mexican series Mujeres Asesinas as Paula Moncada in the episode "Ana y Paula, Ultrajadas". She also starred in the action noir film Give 'Em Hell, Malone and Dario Argento's Giallo. Recently, it has been confirmed that she will have a role in Fast Five, the upcoming fifth film in The Fast and The Furious series.