Mr Bradley said: "In just over a year working with Honda (UK) the brand has really captured me and I relish the challenge, with my new team, of continuing the progress that Ewan has made. We will look to build on our recent sales success which has seen us achieve a record market share and volume for September and finish sixth in the UK market."
Mr Bradley joined Honda (UK) in July 2006, having previously worked for BMW, Volkswagen, Volvo and Vauxhall. In his new role Mr Bradley will report directly to Ken Keir, Honda (UK) managing director.
Mr Ramsay joined Honda as general manager - cars in 2005.
A successor for Mr Bradley will be appointed in the next few weeks.