Haslett is an unincorporated community in Ingham County in the U.S. state of Michigan. It is a census-designated place (CDP) used for statistical purposes. The population was 11,283 at the 2000 census. Though it has its own school district and post office (ZIP code 48840), Haslett is administered by Meridian Charter Township as the local government unit. Downtown Haslett is located near the intersection of Haslett and Marsh roads.Haslett is most notable for being the home of Lake Lansing.