Carters Brook, also known as Carter Brook, is a small river in central New Jersey that serves as a tributary of Heathcote Brook. Flowing through Somerset and Middlesex counties, it begins near the intersection of Route 518 and Route 27 and runs generally south. Along its course, it crosses Promenade Boulevard and Raymond Road before emptying into Heathcote Brook. As one of the local streams feeding the broader brook system in this part of the state, it forms part of the area's connected watershed.