William Le Lacheur or Guillaume Le Lacheur (15 October 1802 – 27 June 1863), was a Guernsey sea captain who played an important role in the economic and spiritual development of Costa Rica. Le Lacheur is widely credited in Costa Rica with having transformed the economy of the country by establishing a direct regular trade route for Costa Rican coffee growers to the European market, thereby helping to establish the Costa Rican coffee trade.