The boro of South Plainfield's population is 22,897 with a land mass of 8.4 square miles. That's a population density of 2,740 people per square mile.

There are 280 teachers for 3,794 students. The student to teacher ratio is 13.6 to 1 and the student to librarian ratio is 632.3 to 1. 86.3% of the residents are high school graduates and 29.6% are college graduates.

The average age is 38. The median income is $71,824. The average income for households with children is $85,342. Sixty eight point nine percent of the residents are married and 38.7% of them have children.

The boro also has 15 houses of worship.