The company was established in 1946 as the Kasuga Radio Co. Ltd. in Komagane City, Nagano Prefecture, Japan. In 1960, the company was renamed Trio Corporation. In 1963, the first overseas office was founded in Los Angeles County, California, USA.

In the early 1960s, Trio's products were rebranded by the Lafayette Radio Company, with a focus on citizens' band radio.

An importer of Japanese-made electronics RadioShack was A&A Trading Co., and a bilingual Japanese-speaking manager from there, William "Bill" Kasuga partnered with George Aratani and Yoichi Nakase to establish a company that would be the exclusive importer of Trio products.

The name Kenwood was invented by Kasuga as being the combination of "Ken", a name common to Japan and North America that had been tested and proven acceptable to American consumers in the name of Kenmore appliances, and "Wood", referring to the durable substance as well as suggesting a relation to Hollywood, California.