Lafayette (formerly, La Fayette) is a city in Contra Costa County, California, United States. As of 2011, the city's population was estimated to be 24,285. Today Lafayette is known for its wealthy inhabitants and pastoral rolling hills. The town is also known for excellent schools within the highly ranked Acalanes School District. In 2012, estimated median household income in Lafayette was over 150,000 dollars, more than double the statewide average and nearly triple the national average.