As of the latest census, Mullica Township has a population of 6,147, with a density of 104.5 persons per square mile. In the year 2000, the population was 5,912, comprising 4,764 Whites, 371 Blacks, 16 Native Americans, 49 Asians, 7 Pacific Islanders, 196 people of two or more races, and 509 others. The Hispanic population was 975. During the harvest season, the township experiences a population bulge due to an influx of migrant workers. The median age of residents in Mullica Township is 39.9 years.