She started her acting career in Julie Taymor's 1999 London production of The Lion King, as one of the original young Nalas. In 2006, she got a place at Royal Academy of Dramatic Art and the role of Emmie Thibodeaux in the musical Caroline, or Change, for which she was nominated for the Whatsonstage.com Stuart Phillips London Newcomer of the Year award 2007, alongside Andrew Garfield. She went on to star in the lead role in Athol Fugard's UK premiere of Victory for the Peter Hall Company and then went to RADA in September 2007. Bennett-Warner graduated from RADA in 2010, but left early to take on the role of Sophie in Lynn Nottage's Ruined at the Almeida Theatre. Before completing the course she was awarded the prestigious Carleton Hobbs Radio Award. However, due to another job commitment she was unable to join the radio rep. After finishing Ruined, a two-hander with Sinéad Cusack for Sky Arts followed. During this time Bennett-Warner was cast in Michael Grandage's award-winning King Lear as Cordelia, with Derek Jacobi in the title role. Before rehearsals started for King Lear in October, she filmed small parts in Come Fly With Me with David Walliams and Matt Lucas and also in Case Histories alongside Jason Isaacs. Bennett-Warner received an Ian Charleson commendation for King Lear. She then took the role of Denise in D. C. Moore's new play The Swan — in a role that had been written for her – at the National Theatre and then Queen Isabel in Michael Grandage's swan song Richard II at the Donmar Warehouse with Eddie Redmayne in the title role and Andrew Buchan as Bolingbroke. She received positive reviews from the critics, with Kate Bassett from The Independent saying: "Both of them are, in fact, outshone by Pippa Bennett-Warner in the cameo role of Isabel, Richard’s devoted, fiery queen." In 2012, she played the lead role in Vivienne Franzmann's second play The Witness, at the Royal Court Theatre. She received rave reviews with Susannah Clapp from The Observer stating" Always thought Pippa Bennett-Warner had big future. Now she is having it in ‘The Witness’ at Royal Court...There are actresses who are more flashy, who more obviously inflect every detail of a speech. PBW is completely natural. Audiences of course admire her: but they do something else, which is not always the same thing: they believe her”. Bennett-Warner went on to secure a nomination for Best Actress at the Evening Standard Theatre Awards 2012, alongside Cate Blanchett and Dame Eileen Atkins and was named as one of the 1000 Most Influential Londoners in 2012 in the category "Generation Next" by The Evening Standard. In 2016, she narrated Zadie Smith's book Swing Time. Bennett-Warner is an Ambassador for The Theatres Trust.
