Marie Avgeropoulos made her debut in the 2009 American teen romantic comedy film ‘I Love You, Beth Cooper’ directed by Chris Columbus. The film was met by negative reviews from critics and performed poorly at the box office. That same year, she also appeared in the Episode: "After School Special" of the American dark fantasy drama television series, ‘Supernatural.’ In 2010, she appeared in the Chris Columbus-directed action-fantasy film ‘Percy Jackson & the Olympians: The Lightning Thief.’ The film opened to a mixed reception but did decent business at the box office. The following year, she starred as ‘Allison’ in the American comedy-drama film ‘50/50’ directed by Jonathan Levine. The film saw critical acclaim upon release and was a major financial success. She next appeared in television series and films like ‘Fugitive at 17’ (2012), ‘Walking the Halls’ (2012), ‘The Inbetweeners’ (2012), ‘90210’ (2013), and ‘Cult’ (2013). In 2014, she joined the main cast of the American post-apocalyptic science fiction drama television series ‘The 100’ where she played the role of ‘Octavia Blake.’ The show ran for 6 years and aired its final episode in 2020.
In 2015, she starred as ‘Nikki’ in the American action film ‘Tracers’ directed by Daniel Benmayor. The film received mixed reviews from critics. That same year, she also received a ‘Leo Award’ nomination for her performance as ‘Cheryl’ in the Canadian thriller film ‘Numb.’ She continued to star in films like ‘A Remarkable Life’ (2016), ‘Dead Rising: Endgame’ (2016), and ‘Wonder Woman: Bloodlines’ (2019). She was last seen in the 2020 American science fiction martial arts film ‘Jiu Jitsu’ where she played the role of ‘Myra.’ The film received mostly negative reviews from critics.