Lacey Township is a township in Ocean County, New Jersey and is considered part of the Jersey Shore and South Jersey regions. As of the 2010 United States Census, the township's population was 27,644, reflecting an increase of 2,298 (+9.1%) from the 25,346 counted in the 2000 Census, which had in turn increased by 3,205 (+14.5%) from the 22,141 counted in the 1990 Census. The 2010 population was the highest recorded in any decennial census. It was named for Continental Army General John Lacey.
Lacey Township was incorporated as a township by an act of the New Jersey Legislature on March 23, 1871, from portions of Dover Township (now known as Toms River Township) and Union Township (now Barnegat Township). Portions of the township were taken on June 23, 1933, to form the borough of Island Beach (which is now Island Beach State Park, part of Berkeley Township). The township was named for Revolutionary War brigadier general John Lacey, who developed Ferrago Forge in 1809.