Alfred Stieglitz's New York gallery was called 291. The name came from its address at 291 Fifth Avenue in Manhattan. Stieglitz operated the gallery from 1905 until 1917, using it to introduce American audiences to photography and European modern art.
The gallery was initially associated with the Photo-Secession movement, which promoted photography as a fine art. It later exhibited work by influential artists including Pablo Picasso, Henri Matisse, Auguste Rodin, and Georgia O'Keeffe. Stieglitz organized O'Keeffe's first solo exhibition there in 1917.
The gallery closed after Stieglitz moved his exhibition activity elsewhere, but its influence continued through his later spaces, including the Intimate Gallery and An American Place. The title 291 is sometimes mistaken for a gallery name based on an artist or movement. It was simply the street number of the Fifth Avenue location, a memorable example of how an address became an institution's identity.