The Royal River is a small river, 39 miles (63 km) long,[1] in southern Maine, United States. The river originates in Sabbathday Pond in New Gloucester and flows northeasterly into Auburn and then southerly through New Gloucester, Gray and North Yarmouth into Casco Bay at Yarmouth. The river is bridged by Interstate 95 and U.S. Route 202 before leaving New Gloucester, then by the Maine Central Railroad "Back Road" and the Grand Trunk Railway in Auburn, and then again by the Grand Trunk Railway and by State Route 231 when it returns to New Gloucester. The river is bridged twice more by the Maine Central Back Road in Gray. In North Yarmouth, the river is bridged again by State Route 231 and by State Route 9, and in Yarmouth it is crossed by the Maine Central Railroad "Lower Road", again by the Grand Trunk Railway, by U.S. Route 1 and, at its mouth, by State Route 88 and Interstate 295.
The river is named after William Royall, one of the first European settlers in the area, though the official form of its name omits the second L. The river is mentioned in several of Maine-native Stephen King's novels, including The Body, when the boys cross the Royal River, only to be attacked by leeches. The McKin Company Superfund site was within the Royal River watershed.[2]