She is known for portraying Zoë Walker in White Lines, Max Meladze in The Recruit, Lucrezia in Da Vinci's Demons, Meredith Quill in Guardians of the Galaxy and its sequel Guardians of the Galaxy Vol.

[6] In 2011, she appeared in the Cinemax/Sky TV drama Strike Back: Project Dawn for two episodes, as the kidnapped daughter of an illegal arms dealer.

She appears in the ITV series, The Level, and played Vivian Wembley in the 2017 film Transformers: The Last Knight.

[11] In 2021, Haddock starred in a Christmas marketing campaign for British furniture and home accessories retailer OKA.

Haddock married English actor Sam Claflin in July 2013 after dating for two years.