Mullica Township officially came into existence at a meeting held at Pleasant Mills on February 21, 1838. Formed from the western section of Galloway Township, Mullica originally included the greater part of the Town of Hammonton and a portion of Egg Harbor City. The township and its famous river were officially named after Eric Mullica, a Swedish plantation owner who lived in Lower Bank during the seventeenth century. He later moved to Mullica Hill. The Elwood section of the Township was first called Weymouth Station. However, in order to have a post office, the name was changed to Elwood after Elwood Matlack. There are still historically significant areas remaining in the township, some dating back to the early 1700's.

Mullica Township had a population of 5912 in 2000 -- 104.5 persons per square mile. Of the 2000 population, 4764 were white, 371 black, 16 Native American, 49 Asian, 7 Pacific Islanders, 196 were of two or more races, and 509 were "other". The Hispanic population was 975. The Township experiences a population bulge due to an influx of migrant workers during the harvest season. The median age in Mullica Township is 39.9 years.

The form of government in the Township of Mullica has been established as the Committee Form. The Township is governed by a committee consisting of five elected members - each of whom serves a three-year term. The mayor is selected each year by the Committee, and presides over the meetings.