Penns Neck is an unincorporated community located within West Windsor Township in Mercer County, in the U.S. state of New Jersey.

The Princeton Branch rail line, known as the Dinky, has run through the area since 1865, and stopped at Penns Neck station until January 1971.

In 1737, concurrent to the settlement of Dutch Neck, Garret Schenck 7 John Covenhoven purchased the land from Penn's sons.

Soon after, the area - bordered by the Stony Brook to the west, the Millstone River to the north, the Assunpink Creek to the south, and Penn Lyle Road to the east - became settled by the Schenck and Covenhoven families.

Following the chartering of Brunswick Pike (Route 1) in 1804 and its completion in 1807, the community began to flourish, seeing the construction of the Red Lion Inn.