Fifth Avenue is a major thoroughfare in the center of the borough of Manhattan in New York City. Lined with expensive park-view real estate and historical mansions, it is a symbol of wealthy New York. Between 34th Street and 59th Street, it is also one of the premier shopping streets in the world, on par with Oxford Street in London, the Champs-Élysées in Paris and Via Montenapoleone in Milan and the presidente Masaryk avenue in Mexico city.

It is consistently ranked as one of the most expensive streets in the world, on a par with Paris, London, and Tokyo lease prices: the "most expensive street in the world" moniker changes depending on currency fluctuations and local economic conditions from year to year. For several years starting in the mid-1990s, the shopping district between 49th and 57th Streets was ranked as having the world's second most expensive retail spaces on a cost per square foot basis after London's Sloane Street..

Fifth Avenue originates at Washington Square Park in Greenwich Village and runs northwards through the heart of Midtown, along the eastern side of Central Park, through the Upper East Side and Harlem, where it terminates at the Harlem River at 142nd Street. Traffic crosses the river on the Madison Avenue Bridge.

Fifth Avenue carries one-way traffic downtown (southbound) from 135th Street to Washington Square Park, with the changeover from two-way traffic taking place on January 14, 1966, at which time Madison Avenue was changed to one way uptown (northbound). Two-way traffic on Fifth Avenue is allowed north of 135th Street only. From 124th Street to 120th Street, Fifth Avenue is cut off by Marcus Garvey Park, with southbound traffic diverted around the park via Mount Morris Park West.

Fifth Avenue is the dividing line for streets in Manhattan. It, for instance, separates East Fifty-ninth Street from West Fifty-ninth Street. As the zero-numbering point for its street addresses, numbers increase in both directions as one moves away from Fifth Avenue, with 1 East Fifty-ninth Street on the corner at Fifth Avenue, and 300 East Fifty-ninth Street located three blocks to the east of it.