Anna Theodora Chancellor is an English actress who has appeared widely on TV, film and in the theatre. She received a nomination for BAFTA TV Award for Best Supporting Actress for her role as Lix Storm in The Hour (2011–2012), and has twice been nominated for Olivier Awards, in 1997 for her performances in Stanley at the National Theatre, and again in 2014 for Private Lives at the Gielgud Theatre. She was also nominated for an award at the Monte-Carlo TV Festival in 2007 and for one at the Broadcasting Press Guild Awards in 2013.

This is a list of the British Academy Television Award for Best Supporting Actress. The British Academy Television Awards were first presented in 1954. They are the UK equivalent to the Emmy Awards in the United States. From 1954 to 1997, film and television awards were presented at one ceremony. Since 1998, two separate ceremonies have been held.