Fifth Avenue is a major and prominent thoroughfare in the borough of Manhattan in New York City. It stretches north from Washington Square Park in Greenwich Village to West 143rd Street in Harlem. It is one of the most expensive shopping streets in the world.

Fifth Avenue carries two-way traffic from 142nd to 135th Street and carries one-way traffic southbound for the remainder of its route. The entire street used to carry two-way traffic until 1966. From 124th to 120th Street, Fifth Avenue is cut off by Marcus Garvey Park, with southbound traffic diverted around the park via Mount Morris Park West. Most of the avenue has a bus lane, though not a bike lane. Fifth Avenue is the traditional route for many celebratory parades in New York City, and is closed on several Sundays per year.

Fifth Avenue was originally only a narrower thoroughfare but the section south of Central Park was widened in 1908. The midtown blocks between 34th and 59th Streets were largely a residential area until the turn of the 20th century, when they were developed as commercial areas. The section of Fifth Avenue in the 50s is consistently ranked among the most expensive shopping streets in the world, and the section between 59th and 96th Streets across Central Park was nicknamed "Millionaire's Row" in the early 20th century due to the high concentration of mansions there. A section of Fifth Avenue running from 82nd to 110th Streets, also alongside Central Park, is also nicknamed Museum Mile due to the large number of museums there.