Gillett is a city in Arkansas County, Arkansas, United States. The population was 691 at the 2010 census. Gillett is the home of the annual Gillett Coon Supper. The Arkansas Post National Memorial is located southeast of the town.The largest alligator ever killed in Arkansas was harpooned near Gillett on September 19, 2010. The thirteen-foot one-inch reptile weighed 680 pounds.