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 Road and Marsh Road.
Haslett is most notable for being the home of Lake Lansing. The lake is approximately 500 acres (2.0 km²) in size and features two public parks, allowing access to beaches, fishing, and a boat launch. The Michigan State University Sailing Club and Lansing Sailing Club are located on Lake Lansing. From 1934 until 1974, an amusement park operated near the lake and featured a giant wood roller coaster . In 2007, Business Week ranked Haslett 42nd on their list of 'Best Places to Raise Your Kids.'
According to the United States Census Bureau, the CDP has a total area of 9.1 square miles (23.5 km²), of which, 8.3 square miles (21.6 km²) of it is land and 0.8 square miles (1.9 km²) of it (8.27%) is water.