Lafayette Township is a township located in the Skylands Region of Sussex County, New Jersey, United States. As of the 2010 United States Census, the township's population was 2,538, reflecting an increase of 238 from the 2,300 counted in the 2000 Census, which had in turn increased by 398 from the 1,902 counted in the 1990 Census.Lafayette was formed as a Township based on an Act of the New Jersey Legislature on April 14, 1845, from part of Frankford Township and Newton Township, based on the results of a referendum held that same day. The township was the first in the country to be named for Gilbert du Motier, Marquis de Lafayette, the French general and statesman who served in the Continental Army during the American Revolutionary War.The township is crossed by Route 15 and Route 94.