U.S. Route 20 (US 20) is a part of the United States Numbered Highway System that runs from Newport, Oregon, to Boston, Massachusetts. In the U.S. state of New York, US 20 extends 372.32 miles (599.19 km) from the Pennsylvania state line at Ripley to the Massachusetts state line in the Berkshires. US 20 is the longest surface road in New York. It runs near the Lake Erie shore from Ripley to Buffalo and passes through the southern suburbs of Buffalo, the Finger Lakes, the glacial moraines of Central New York, and the city of Albany before crossing into Massachusetts. US 20 connects to all three major north–south Interstate Highways in Upstate New York: Interstate 390 (I-390) near Avon, I-81 south of Syracuse, and I-87 in Albany by way of NY 910F.

Ripley is a town on Lake Erie in the westernmost part of Chautauqua County, New York, United States. The population was 2,310 at the time of the 2020 census. The town was named after Eleazer Wheelock Ripley, a general in the War of 1812. There are no incorporated villages in the town, but there is one census-designated place: the hamlet of Ripley. The town is perhaps best known as being the western terminus of the New York State Thruway.