Cedar Knolls is an unincorporated area located within Hanover Township in Morris County, New Jersey. It is part of Hanover Township along with Whippany. Though Cedar Knolls has its own post office, many residents have Morris Plains postal addresses, which confuses those seeking to know the borders of Cedar Knolls. The Trailwood section of Cedar Knolls is known for its typically large homes and affluent residents. Residents of Cedar Knolls attend Mountview Road School, which also has a Morris Plains postal address.