Route 237 was introduced in the early 1930s when it was totally different from what it is today. It started at Hounslow Garage, followed the current route 235 and finished at Chertsey station. Single-deck one man buses were used on the route.
In 1978, the route was extended to replace the Shepherd's Bush Green section of route 117 and the section between Sunbury and Chertsey Station was withdrawn. (Route 117 was, in 1962, itself a replacement of trolleybus service 657 between Hounslow and Shepherd's Bush.) It was converted to double-deck Routemaster operation at the same time, a rare case of a route being converted from one person to crew operation.
When the route was converted to OPO in 1987, it mainly used Leyland Olympians also MCW Metrobuses and even the odd single decker.
In 1996, the section between Sunbury Village and Hounslow Heath was withdrawn, being replaced by route 235. By this time there had been enough Metrobuse to allow the Olympians to be converted to the 140, although the latter still did reular runs on the route. In 1998 London United lost the contract for route 237 and the route was transferred to Armchair, operated by Leyland Olympians and Northern Counties Palatine-bodied Volvo Olympians even single decker Darts did some workings. In 2002 the contract was renewed and the route was converted to low-floor double-deck operation using Dennis Trident 2s, with the last Olympian running on the 3 January 2003. In early 2006 the contract was handed over to Metroline and the existing vehicles since have been painted into Metroline livery.
