Anna Maxwell Martin (born Anna Charlotte Martin; 10 May 1977), sometimes credited as Anna Maxwell-Martin, is an English actress. She won two British Academy Television Awards, for her portrayals of Esther Summerson in the BBC adaptation of Bleak House (2005) and N in the Channel 4 adaptation of Poppy Shakespeare (2008). She is also known for her roles as DCS Patricia Carmichael in BBC One crime drama Line of Duty (2019–2021) and Kelly Major in Code 404 (2020–2022). From 2016-2022, Martin starred in the BBC comedy Motherland, for which she was nominated for the BAFTA Award for Best Female Comedy Performance.

Martin's theatre work includes the role of Lyra Belacqua in the production of His Dark Materials (2003–2004) at the National Theatre.