Route 240 was introduced in the 1930s between Golders Green and Edgware stations and replaced the former London General Omnibus Company route 104.

The only single-decker version of the LS (London Six) type bus ran on route 240.

[2] Upon being re-tendered, the route was retained by Metroline with a new contract commencing on 30 April 2005.

[3] Route 240 was retained by Metroline on 18 August 2011.

[4] Route 240 operates via these primary locations:[5]