The Washington–Franklin Issues are a series of definitive U.S. Postage stamps depicting George Washington and Benjamin Franklin, issued by the U.S. Post Office between 1908 and 1922. The distinctive feature of this issue is that it employs only two engraved heads set in ovals—Washington and Franklin in full profile—and replicates one or another of these portraits on every stamp denomination in the series. This is a significant departure from previous definitive issues, which had featured pantheons of famous Americans, with each portrait-image confined to a single denomination. At the same time, this break with the recent past represented a return to origins. Washington and Franklin, after all, had appeared on the first two American stamps, issued in 1847, and during the next fifteen years, each of the eight stamp denominations available featured either Washington or Franklin.

A definitive stamp is a postage stamp that is part of the regular issue of a country's stamps, available for sale by the post office for an extended period of time and designed to serve the everyday postal needs of the country. The term is used in contrast to a "provisional stamp", one that is issued for a temporary period until regular stamps are available, or a "commemorative stamp", a stamp "issued to honor a person or mark a special event" available only for a limited time. Commonly, a definitive issue or series includes stamps in a range of denominations sufficient to cover current postal rates. An "issue" generally means a set that is put on sale all at the same time, while a "series" is spread out over several years, but the terms are not precise. Additional stamps in a series may be produced as needed by changes in postal rates; nevertheless some values may be permanently available, regardless of prevailing rates; examples include 1c or 1p and $1 or £1.