The United Nations Philatelists, Inc. is an organization of philatelists devoted to the collection, study and exhibition of the issues of the United Nations Postal Administration, the postal history of the United Nations, the issues and postal history of its branches, specialized agencies and forerunners, as well as the world-wide topical issues that call attention to the United Nations, its agencies and programs.

In support of these activities UNPI issues a bi-monthly journal "The Journal of United Nations Philatelists", which is typically twenty-four pages long and keeps members informed about United Nations philately, including club activities and meetings, on-going research in and new items of philatelic interest to United Nations philatelists.