Clayton is a borough in Gloucester County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 8,179, reflecting an increase of 1,040 from the 7,139 counted in the 2000 Census, which had in turn increased by 984 from the 6,155 counted in the 1990 Census.Jacob Fisler, who purchased much of the area that is now Clayton, established a community called Fislertown in 1850 that grew substantially after he opened a glass factory. What is now Clayton was originally formed as Clayton Township, which was created on February 5, 1858, from portions of Franklin Township. Portions of the township were taken to form Glassboro Township on March 11, 1878. Clayton was formed as a borough by an act of the New Jersey Legislature on May 9, 1887, from portions of Clayton Township. The remainder of Clayton Township was absorbed by the Borough of Clayton on April 14, 1908, and the township was dissolved.