Robert Lewis Glenister is an English actor. He is best known for his television roles as Ash "Three Socks" Morgan in the crime drama series Hustle (2004–2012) and Nicholas Blake in the spy drama series Spooks (2006–2010).

Hustle is a British crime drama television series starring Adrian Lester, Robert Glenister and Robert Vaughn. Created by Tony Jordan, it was produced by Kudos Film and Television, and broadcast on BBC One in the United Kingdom. The show premiered on 24 February 2004, and ran for eight series, with its final episode aired on 17 February 2012. The show's premise is on a group of con artists who specialise in "long cons" – extended forms of deceptive frauds that require greater commitment, but offer higher rewards than simple confidence tricks. The show's most notable qualities are plots that involve behind-the-scenes action that the viewers are unaware of until near the end of an episode, along with fantasy scenes and occasional breaches of the fourth wall by the main actors.