Marlboro is a census-designated place (CDP) located in Stow Creek Township on the northwestern edge of Cumberland County, in the U.S. state of New Jersey. It is bordered to the northwest, across Sarah Run, by Quinton Township in Salem County. The CDP contains the unincorporated communities of Marlboro and Campbells Corner.
New Jersey Route 49 passes through the CDP, leading southeast to Bridgeton, the Cumberland county seat, and northwest to Salem.
Marlboro was first listed as a census designated place in the 2020 U.S. census.
As of 2020, the population was 127.
Students are zoned to Stow Creek Township School District (for elementary school) and Cumberland Regional School District (for high school).
The Stow Creek school district and the Greenwich Township School District have a cooperative agreement in which all students in grade levels Kindergarten through 4 in both school districts attend the Greenwich Township school facility, Morris Goodwin School, while all students in grades 5-8 in both school districts attend the Stow Creek school facility, Stow Creek School.