Cambridge Circus, London
Cambridge Circus is a junction at the intersection of Shaftesbury Avenue and Charing Cross Road in central London. The junction is situated approximately halfway between Tottenham Court Road station (at St Giles Circus) and Leicester Square. Consisting of listed Georgian and Victorian buildings, it is home to a number of social and cultural institutions including the Palace Theatre and The Ivy which is popular with celebrities and artists.
The Palace Theatre is located on the west side of the junction, while The Ivy and a number of private clubs are accessible from the south of Cambridge Circus. The listed Georgian and Victorian buildings which make up the junction have featured in a number of espionage and spy films and books. 
In his espionage novels, author John le Carré placed the headquarters of the fictionalised British intelligence service based on MI6 in buildings on Shaftesbury Avenue and Cambridge Circus; it is from this that Le Carré's nickname for the agency, "The Circus", derives. The BBC's Gordon Corera notes that the entrance described by Le Carré most closely resembles that of 90 Charing Cross Road, just north of Cambridge Circus. The actual MI6 has never occupied premises in or near Cambridge Circus.
Cambridge Circus was the location of Marks & Co. booksellers, located at 84 Charing Cross Road, which featured in Helene Hanff's 1970 book 84, Charing Cross Road, which has subsequently been adapted into a stage play, a television play, and a 1987 movie starting Anne Bancroft, Anthony Hopkins, and Judi Dench. Hanff's book, as well as her other work The Duchess of Bloomsbury (1973), detail her several decades long mail correspondence with Frank Doel, a bookseller at Mark & Co.
Cambridge Circus has featured as location in the following productions:
- Christopher Howse (1 May 2007). "Exactly where is the Circus?". The Telegraph. Archived from the original on 10 May 2012.
- John Le Carré Call for the Dead
- Gordon Corera (11 September 2011). "Tinker Tailor Soldier Spy: John Le Carre and reality". BBC News. Retrieved 31 July 2015.
- "Buildings". Secret Intelligence Service (MI6). Archived from the original on 4 July 2015. Retrieved 31 July 2015.