A commemorative stamp is a postage stamp, often issued on a significant date such as an anniversary, to honor or commemorate a place, event or person. The subject of the commemorative stamp is usually spelled out in print, unlike definitive stamps which normally depict the subject along with the denomination and country name only. Many postal services issue several commemorative stamps each year, sometimes holding first day of issue ceremonies at locations connected with the subjects. Commemorative stamps can be used alongside ordinary stamps. Unlike definitive stamps that are often reprinted and sold over a prolonged period of time for general usage, commemorative stamps are usually printed in limited quantities and sold for a much shorter period of time, usually until supplies run out.

There are several candidates for the title of first commemorative. A 17-cent stamp issued in 1860 by New Brunswick, showing the Prince of Wales in anticipation of his visit is one possibility. One of the most notable examples of the Columbus commemoratives was released when The United States issued its first commemorative stamp in 1893, the $1 Columbian Exposition issue, "Isabella pledging her jewels", one of a set of 16 commemoratives issued to celebrate the 400th anniversary of Christopher Columbus's arrival in the New World in 1492.