Nicola Walker (born 15 May 1970) is an English actress, known for her starring roles in various British television programmes from the 1990s onwards, including that of Ruth Evershed in the spy drama Spooks from 2003 to 2011. She has also worked in theatre, radio and film. She won the 2013 Olivier Award for Best Supporting Actress for the play The Curious Incident of the Dog in the Night-Time, and has twice been nominated for the BAFTA TV Award for Best Supporting Actress for the BBC drama Last Tango in Halifax.
Walker was born in Stepney in the East End of London and has an older brother. She attended Saint Nicholas School, Old Harlow, and Forest School, Walthamstow, and undertook acting classes from age 12 in order to speak to boys. Interviewed in 2014 by The Guardian, she said, "I was really encouraged by my mother. My dad thought it was a ridiculous thing to do."
Walker then attended New Hall, Cambridge, where she started her acting career with the Cambridge Footlights. Her contemporaries included Spooks writer David Wolstencroft and comedian Sue Perkins, who were all part of the 1990 national tour. Perkins, then an older undergraduate, was assigned to be her "college mother", although Walker later said: "She was the worst college mother I could have had. They're meant to hold your hand. She asked to borrow my bike, got drunk, and I never saw it again." Walker acted on stage as Perkins's stooge and years later their partnership was resumed when Perkins cast Walker in her sitcom Heading Out.
Offered a place at the Royal Academy of Dramatic Art on graduation from Cambridge, Walker already had some roles and an agent, so she decided to pursue her acting career. Based in London, she shared a flat with Perkins, Sarah Phelps, and Emma Kennedy, and acted at the Edinburgh Festival and the London Festival Fringe.
Walker's first major television roles were in 1997, as Gypsy Jones in Channel 4's adaptation of A Dance to the Music of Time, and as English teacher Suzy Travis in two series of Steven Moffat's school-based sitcom Chalk. She has also appeared in guest roles in episodes of series such as Dalziel and Pascoe, Jonathan Creek, Pie in the Sky, and Broken News.
She played the leading part of DI Susan Taylor in the ITV thriller serial Touching Evil in 1997, co-starring opposite Robson Green. She also appeared in its two sequel serials in 1998 and 1999. Also in 1999, she took the lead role in the post-apocalyptic drama serial The Last Train, also screened on ITV (and written by future Spooks writer Matthew Graham). Also in 2003, Walker played Molly in the BBC Radio adaptation of Neuromancer by William Gibson.
In 2003, with the production team of Kudos Television looking to replace the character played by Jenny Agutter in Series 1 of Spooks, the part of Ruth Evershed was specially written for Walker from Series 2. She remained with the show until the fifth series, during the production of which it was announced she was expecting her first child and would be leaving. She returned in 2009 and continued until the series ended in 2011. Benji Wilson of The Daily Telegraph praised Walker's performance, stating: "an actress who has squeezed every drop out of TV’s greatest ever largely dumbstruck doormat for the best part of a decade. Her scenes with Peter Firth, another fine player, have become self-contained little bubbles of weltschmerz within every recent episode".
In 2009, she appeared as a maid in a new BBC adaptation of Henry James' The Turn of the Screw, which also starred Michelle Dockery and Sue Johnston. In 2010, Walker appeared as a beleaguered wife (Linda Shand) of a murderer in an episode of the BBC1 crime thriller Luther.
In February and March 2013, Walker reunited with her former Cambridge Footlights colleague Sue Perkins in the BBC comedy Heading Out. She then appeared in the second series of Prisoners' Wives and the third series of Scott & Bailey playing Helen Bartlett.
In 2015, she appeared as Jackie "Stevie" Stevenson, the colleague of DI John River played by Stellan Skarsgård, in the BBC drama series River. She also starred as DCI Cassie Stuart, alongside actor Sanjeev Bhaskar as DS Sunil "Sunny" Khan, in the ITV drama series Unforgotten, which returned for a third series in 2018.
Walker won an Olivier Award in 2013 for Best Supporting Actress in her role as Judy, the main character Christopher's mother, in The Curious Incident of the Dog in the Night-Time. The play won seven Olivier Awards, equalling Matilda the Musical's record win in 2012.
In 2014, she starred alongside Mark Strong and Phoebe Fox in Arthur Miller's play A View from the Bridge, at the Young Vic theatre. The play received extremely positive reviews from critics and transferred to Wyndham's Theatre in London's West End in 2015 and to the Lyceum Theatre on Broadway.
In film, Walker's roles have tended to be smaller supporting parts. Her most prominent role has been as the irritating folk singer in Four Weddings and a Funeral (1994), who sings "Can't Smile Without You" at the first wedding. She also appeared in the feature film adaptation of the classic television series Thunderbirds (2004).
In July 2011, Walker played the significant supporting role of Medtech  Liv Chenka in the Big Finish Productions Doctor Who audio drama Robophobia, opposite Sylvester McCoy as the Seventh Doctor. The Chenka character proved popular both with producers and listeners, and in February 2014 Walker returned to the role, this time as a foil for Paul McGann's Eighth Doctor in Dark Eyes 2. The character was sustained throughoutDark Eyes 3 and Dark Eyes 4, at the end of which it was revealed that Chenka was to continue as the Doctor's established travelling companion. In October 2015, Walker again returned to the role in the follow-up 4-volume Doom Coalition and Ravenous. In 2017, she starred in the company's adaptation of the H.G. Wells novel The Shape of Things to Come.
- Relocated – Royal Court Theatre London (2008)
- Gethsemane – National Theatre London (2008/9)
- Season's Greetings – National Theatre London (2010/11)
- Di and Viv and Rose – Hampstead Theatre (Downstairs) London (2011)
- The Curious Incident of the Dog in the Night-Time – National Theatre London (2012) for which she won the 2013 Olivier Award in the category 'Best Actress in a Supporting Role'
- A View from the Bridge – Young Vic/Wyndham's Theatre (West End) London (2014/15), Lyceum Theatre on Broadway (2015/16)