Jackson Township is a township in Union County, Arkansas, United States. Its total population was 758 as of the 2010 United States Census, a decrease of 1.56 percent from 770 at the 2000 census.According to the 2010 Census, Jackson Township is located at 33°03′07″N 92°37′33″W (33.051999, -92.625904). It has a total area of 58.338 square miles (151.09 square kilometers); of which 58.116 sq mi (150.52 km2) is land and 0.222 sq mi (0.57 km2) is water (0.38%).