Britain's best known and longest established sidecar maker. It is unique in currently producing a range of traditional sidecars utilizing much of the tooling and manufacturing methods as in times past. These are joined by updated and new models to suit all ages and size of motorcycles.

All U.S. sidecars are mounted on the right hand side.

Watsonian began manufacturing sidecars in 1912 in the Watson family home. From there the company moved to Branwood, then on to a bona fide factory in Albion Road Greet, Birmingham, England. In 1983, the business moved to Northwick Park in Gloucestershire. The world's oldest sidecar company and the leading manufacturer of sidecars, Watsonians were world racing sidecar champions in the 1950s.

Directors Ron Watson (son of the founder) and Cliff Bennett (who joined the firm in 1926 as a 14 year-old lad) have sold the company and its assets to Doug Bingham, who has been Watsonian's American distributor since the early 1970s. Cliff and Ron are retiring. Doug's partner, along with Cliff's son-in-law, Peter Machin, who started as company secretary in 1973, and has been involved with day-to-day administration. A third partner is Cyril Heath, with the company since 1949, who is also vice president of the British Sidecar Federation.

In 1988 there was a merger of the Watsonian and Squire sidecar companies to facilitate competition in the Common Market.