Dayton is an unincorporated community and census-designated place (CDP)[9] in South Brunswick Township, Middlesex County, New Jersey, in the United States.

[12] Dayton has a post office with its own ZIP Code (08810) that encompasses the entire CDP, as well as some surrounding areas.

[4] The community was named for William L. Dayton, a local attorney who later served in the United States Senate,[13][14] or for Jonathan Dayton, the youngest person to sign the United States Constitution, who later served as a U.S. senator from New Jersey.

[15] The area had been known as "Cross Roads" and was renamed in 1866 to avoid confusion with mail that was sent to another post office that shared the name.

[13][14] Dayton is in southwestern Middlesex County, in east-central South Brunswick Township.

U.S. Route 130 forms the eastern border of the Dayton CDP and leads north 10 miles (16 km) to New Brunswick, the Middlesex county seat, and south 7 miles (11 km) to Hightstown.

[1] The community drains southwest toward Devils Brook, a west-flowing tributary of the Millstone River, and northeast toward Lawrence Brook, which flows northeast to join the Raritan River east of New Brunswick.

The 2010 United States census counted 7,063 people, 2,288 households, and 1,901 families in the CDP.