is an English actress. She is best known for starring as Lady Mary Crawley in the ITV television period drama series Downton Abbey (2010–2015), for which she was nominated for a Golden Globe Award and three consecutive Primetime Emmy Awards for Outstanding Lead Actress in a Drama Series. She reprised her role in the films Downton Abbey (2019) and Downton Abbey: A New Era (2022).

After graduating from the Guildhall School of Music and Drama, Dockery made her professional stage debut in His Dark Materials in 2004. For her role as Eliza Doolittle in a 2007 London revival of Pygmalion, she was nominated for the Evening Standard Award. For her role in the 2009 play Burnt by the Sun, she earned an Olivier Award nomination for Best Supporting Actress.

Dockery has appeared in the films Hanna (2011), Anna Karenina (2012), Non-Stop (2014), and The Gentlemen (2019). She has also played lead roles in the western miniseries Godless (2017), for which she received her fourth Emmy nomination, and the drama miniseries Defending Jacob (2020) and Anatomy of a Scandal (2022).