Luddington was born in Ascot, Berkshire, and at age 11 began studying at the Italia Conti Academy in England. She moved to suburban Austin, Texas, United States when she was fourteen, and attended Westwood High School for one year. She returned to England after one year, and completed her education at TASIS, The American International School in England, in July 2002. When she was nineteen, Luddington enrolled in Susquehanna University in Pennsylvania. However, she had not visited the university before she arrived as a student, and after six months she left and transferred to the New York Film Academy. In 2003, she was part of the school's first one-year acting class program. After training as an actor, Luddington then returned to England before moving to Los Angeles to pursue a career in acting.
Luddington has worked mainly in the United States. Luddington joined the cast of the Showtime comedy-drama series Californication for its fifth season, playing a nanny. She also joined the cast of season five of the HBO vampire drama True Blood, as Claudette Crane, a faerie. In July 2012, Luddington joined the cast of the ABC medical drama Grey's Anatomy as Dr. Jo Wilson, in a recurring role. In June 2013 it was announced that she would be a series regular from season ten onward. In October 2012, Luddington appeared on a Hallowe'en special of E!'s popular fashion programme Fashion Police, alongside a panel of Joan Rivers, Kelly Osbourne, George Kotsiopoulos, and Kris Jenner.
''Tomb Raider''
In June 2012, Crystal Dynamics confirmed Luddington would voice Lara Croft in the video gameTomb Raider. Luddington originally went into the audition for Lara thinking she was auditioning for a project called "Krypted" with a character called Sara. In June 2014, it was revealed that a sequel was in production, titled Rise of the Tomb Raider, and Luddington confirmed on her Twitter account that she would be returning to voice and motion capture Lara in the new game. Luddington also returned to reprise her role for Shadow of the Tomb Raider, released in September 2018.
Personal life
On 21 October 2016, Luddington announced that she was expecting a baby with fellow actor and boyfriend Matthew Alan. Their daughter, Hayden, was born in March 2017. Luddington announced the engagement on 17 January 2018. She also became an American citizen that November the same year. Luddington and Alan married on 17 August 2019. On 9 March 2020, Luddington announced her second pregnancy via Instagram.