Whilst training at RADA, Dillon appeared in several productions staged there, including: Hamlet and The Tempest by William Shakespeare, The Devils by John Whiting, The Devil's Law Case by John Webster, Yentl by Leah Napolin and The Playboy of the Western World by J. M. Synge. Her first theatrical job after graduation was the title role in Euripides' Iphigeneia at Aulis at the Crucible Theatre, Sheffield. She then went on to appear in numerous theatre productions, including as Hilda Wangel in The Master Builder by Henrik Ibsen at the Albery Theatre, London. Desdemona in Othello. Ibsen's Hedda Gabler as Thea and Period of Adjustment by Tennessee Williams In 2007, she returned to the Crucible to play Celia in Shakespeare's As You Like It during February and Varya in Chekhov's The Cherry Orchard during March. She then starred in the National Theatre's revival of Noël Coward's Present Laughter and The Hour We Knew Nothing of Each Other. She also appeared in Anna Mackmin's 2008 West End revival of Under the Blue Sky by David Eldridge. In 2009, Dillon starred in When the Rain Stops Falling at the Almeida, and in 2010 in Design for Living and its successor production A Flea In Her Ear at the Old Vic. Eldridge created the role of Lucy in The Knot of the Heart, presented at the Almeida in March 2011, specifically for Dillon. In early 2012, Dillon played the role of Katharina in the Royal Shakespeare Company Stratford and touring production of The Taming of the Shrew. In 2014, she starred as Moll Cutpurse in The Roaring Girl with the RSC. In December 2015 she took the title role in Hapgood for director Howard Davies at the Hampstead Theatre.
Television
Dillon is now best known for her role as Mary Smith in the British television seriesCranford on BBC One where she starred alongside Michael Gambon, Imelda Staunton, Jim Carter and Judi Dench. She also starred in the 2003 drama Cambridge Spies and the 2004 TV film, Hawking, both of which were also for the BBC. She appeared in The Jury in autumn 2011 and appeared as Melinda in the third episode of Dirk Gently for BBC Four in March 2012.
In 2008 Dillon duetted with British singer-songwriter Tim Arnold on his song "She's Made A Gentleman Of Me".
Radio
In 2011 Dillon read a Jarvis and Ayres production of Hilda Richards' 1939 story "Jemima Gets Them Guessing" for BBC Radio 4's Afternoon Reading show, on 9 March. She has undertaken the following roles in productions by Jarvis and Ayres for BBC Radio 4 of: Honey Rider in "Dr. No" on 24/5/2008; Tilly Masterson in "Goldfinger" on 3/4/2010; Tracy Draco in "On Her Majesty's Secret Service" on 3/5/2014; Tiffany Case in "Diamonds are Forever"" on 25/7/15 and Patricia Fearing in "Thunderball" on 10/12/2016.
Awards
In 2003 she was nominated for the Evening Standard Award for Outstanding Newcomer of the Year for the performance she gave in a production of Ibsen's The Master Builder. She won that year's Ian Charleson Award, in part, for that performance.
