U.S. Route 209 (US 209) is a 211.74-mile (340.76 km) long U.S. Highway in the states of Pennsylvania and New York. Although the route is a spur of US 9, US 209 never intersects US 9, coming within five miles of the route and making the short connection via New York State Route 199 (NY 199). The southern terminus of the route is at Pennsylvania Route 147 (PA 147) in Millersburg, Pennsylvania. The northern terminus is at US 9W north of Kingston in Ulster, New York, where the road continues east as NY 199.

U.S. Route 9 (US 9) is a north–south United States Numbered Highway in the states of Delaware, New Jersey, and New York in the Northeastern United States. It is one of only two U.S. Highways with a ferry connection ; the other is US 10. US 9 is signed east–west in Delaware and north–south on the rest of its route. The southern terminus of the route is in Laurel, Delaware, at an intersection with US 13, while the highway's northern terminus is at a junction with Interstate 87 (I-87) in Champlain, New York, where the old roadway continues north as the unsigned New York State Route 971B (NY 971B), which ends in a cul-de-sac just short of the Canadian border.