U.S. Route 11 or U.S. Highway 11 (US 11) is a major north–south United States Numbered Highway extending 1,645 miles (2,647 km) across the eastern U.S. The southern terminus of the route is at US 90 in Bayou Sauvage National Wildlife Refuge in eastern New Orleans, Louisiana. The northern terminus is at the Rouses Point–Lacolle 223 Border Crossing in Rouses Point, New York. The route continues across the border into Canada as Route 223. US 11, created in 1926, maintains most of its original route. The route north of Knoxville, Tennessee, follows a route similar to Interstate 81 (I-81). While it is signed as a north–south route, it physically travels in a northeast–southwest direction.

The United States Numbered Highway System is an integrated network of roads and highways numbered within a nationwide grid in the contiguous United States. As the designation and numbering of these highways were coordinated among the states, they are sometimes called Federal Highways, but the roadways were built and have always been maintained by state or local governments since their initial designation in 1926.