The Rahway River Parkway is a greenway of parkland along the banks the main stem Rahway River and its tributaries in Union County, New Jersey, United States. Created in the 1920s, it was one of the inaugural projects of the newly-created Union County Parks Commission. It was designed by the Olmsted Brothers firm, sons of landscape architect Frederick Law Olmsted. The Rahway River Greenway plan expands on the original design. Many of the crossings of the river are late 19th century or early 20th century bridges. The East Coast Greenway uses paths and roads along the parkway.