The Bow Street Runners were the law enforcement officers of the Bow Street Magistrates' Court in the City of Westminster. They have been called London's first professional police force. The force originally numbered six men and was founded in 1749 by magistrate Henry Fielding, who was also well known as an author. His assistant, brother, and successor as magistrate, John Fielding, moulded the constables into a professional and effective force. Bow Street Runners was the public's nickname for the officers although the officers did not use the term themselves and considered it derogatory. The group was disbanded in 1839 and its personnel merged with the Metropolitan Police, which had been formed ten years earlier.

Bow Street Magistrates' Court became one of the most famous magistrates' court in England. Over its 266-year existence it occupied various buildings on Bow Street in Central London, immediately north-east of Covent Garden. It closed in 2006 and its work moved to a set of four magistrates' courts: Westminster, Camberwell Green, Highbury Corner and the City of Westminster Magistrates' Court. The senior magistrate at Bow Street until 2000 was the Chief Metropolitan Stipendiary Magistrate.