Eleventh Avenue is a north–south thoroughfare on the far West Side of the borough of Manhattan in New York City, located near the Hudson River. Eleventh Avenue originates in the Meatpacking District in the Greenwich Village and West Village neighborhoods at Gansevoort Street, where Eleventh Avenue, Tenth Avenue, and West Street intersect. It is considered part of the West Side Highway between 22nd and Gansevoort Streets.

Between 59th and 107th Streets, the avenue is known as West End Avenue. Both West End Avenue and Eleventh Avenue are considered to be part of the same road.

Between Gansevoort Street and West 22nd Street on the far West Side of Manhattan in New York City, near the Hudson River, Eleventh Avenue is part of the West Side Highway, a wide boulevard. At a split with Twelfth Avenue/West Side Highway at West 22nd Street, Eleventh Avenue continues as a standard-width avenue.

Following the split, Eleventh Avenue is two-way traffic for access to 23rd Street, as well as for 24th Street to access Chelsea Piers. North of 24th Street, Eleventh Avenue is one-way southbound from 24th to 34th Streets, where two-way traffic resumes for access to the Lincoln Tunnel. The segment between approximately 39th and 59th Streets is home to the largest concentration of auto dealerships in Manhattan.^{[citation needed]} Eleventh Avenue again becomes one-way southbound between 40th and 57th Streets; two-way traffic resumes north of 57th Street.

The portion north of 59th Street is called West End Avenue, which has mixed commercial and residential use. The northern 2 miles (3.2 km) are a sedate Upper West Side residential street ending at Straus Park, 107th Street, and Broadway. Traffic is bidirectional, except for the northernmost block, north of 106th Street.

The West Side Line of the New York Central Railroad once had on-street running along part of Eleventh Avenue, which, along with Tenth Avenue, become known as "Death Avenue" because of the large number of deaths that occurred due to train–pedestrian collisions. In 1929, the city, the state, and New York Central agreed on the West Side Improvement Project, conceived by Robert Moses, and allocated funds for an elevated railway that would eliminate the grade crossings and alleviate the problems along Tenth and Eleventh Avenues; it also included construction of the West Side Elevated Highway.

Meanwhile, the avenue's West End Avenue section was originally created in the 1880s as the northern extension of Eleventh Avenue, and was intended to be a commercial street serving the residents of the mansions to be constructed along Riverside Drive. When West End Avenue was named in the 1880s, the Upper West Side was fairly sparsely populated, and that upper portion of the avenue, subsequently, was called the "West End" because of its separation from the core of the city. Seeking to distinguish the area from the factories and tenements below 59th Street, a group of real estate developers renamed the northern portions of the West Side's avenues.

Portions of both West End Avenue and Eleventh Avenue were run down in the mid-20th century, with single room occupancy hotels, prostitutes and drug addicts a common sight. The city's economic comeback in the 1980s brought recovery and gentrification.