is a town in St. John Township, Lake County, Indiana, United States. The population was 13,895 at the 2000 census.
Dyer borders Munster to the north, unincorporated St. John Township to the south, Schererville to the east, and Lynwood and Sauk Village in Illinois to the west. The Illinois state line comprises Dyer's entire western border.
According to the United States Census Bureau, the town has a total area of 6.0 square miles (15.4 km
), all of it land. Dyer is built on mostly flat land with an exception being the steep sand ridge south of US Highway 30. This is the Glenwood Shoreline.