The Commons on Flickr is a project that makes some of the world's greatest public photography archives available at no cost. Thousands of photos are available for download and can be used by faculty and students for teaching, research, presentations, online assignments, or publishing.

The project was launched in January of 2008 as a pilot project of the Library of Congress and Flickr, but now is open to any institution that would like to contribute content. The Smithsonian Institution, the New York Public Library, the National Library of New Zealand, and the Swedish National Heritage Board are among the 23 institutions to join the Library of Congress. All participating institutions must agree to make their material freely available and state that there are "no known copyright restrictions" on the images that they share.

The goal of The Commons on Flickr is not only to increase access to publicly-held photograph collections, but also to provide a way for the public to contribute information on the subject material in the form of comments, tags, or metadata, and thus add to our collective knowledge. This participatory, social networking aspect of the project has made it a remarkably successful resource. One contributing institution, Powerhouse Museum, uploaded 1,171 photos in one year (382 were geotagged) from four different archives. They report that these have been viewed over 777,000 times and "that's not even scratching the surface of the amazing extra information and identifications, mashups, new work, and more that has come from the community participation."