Timber Run is a tributary of Rocky Brook in Mercer County, New Jersey in the United States.

[2] This one starts in the middle of a field between Lake Drive and the original alignment of Milford Rd.

It flows west-northwest to a point behind a restaurant located a few hundred feet east of the New Jersey Turnpike.

From there, the creek turns west-southwest, and continues until it drains into a narrow recessed section of Peddie Lake.

Much of this stream is culverted, and parts of its route are diverted around local businesses and Interchange 8 of the Turnpike.