Once Upon a Time... Man (French: Il était une fois... l'homme) is an educational animated television series created and directed by Albert Barillé. It is the first series in the Once Upon a Time... franchise. It explains human history in a format adapted for children, with the action focused around one group of characters which appear in every episode dealing with the problems of the period depicted. Although historical figures would typically appear as themselves, occasionally they inherit the appearance and some of the personality of one of the archetypes. The series is known for explaining historic events to children from different viewpoints as the main characters come from different civilizations.

The series was produced by French studio Procidis in co-production with France Régions (FR3, France), Société Radio-Canada and ACCESS Alberta (Canada), Radiotelevisione italiana (RAI, Italy), the Swiss Broadcasting Corporation (SSR, Switzerland), Radiodiffusion-Télévision Belge and Belgische Radio en Televisie (RTBF and BRT, Belgium), Katholieke Radio Omroep (KRO, Netherlands), Norsk rikskringkasting (NRK, Norway), Sveriges Radio (SR, Sweden), Televisión Española (TVE, Spain), and Tatsunoko Production (Japan) who was the one who made the animation. The series premiered in France on FR3, between 30 September 1978 and 14 April 1979, and it was subsequently broadcast on the channels of the rest of the broadcasters that participated in the production dubbed into their own language.

Once Upon a Time... Man was purchased by most public broadcasting channels in Europe later, and by many other broadcasters in other countries around the world, and is well-known by a significant percentage of the population. The show aired in the United States on the History Channel starting in January 1996.