Michel Johann Théato (22 March 1878, Luxembourg, Luxembourg – 1919, Paris, France) was a Luxembourgian athlete, and the winner of the marathon at the 1900 Olympics in Paris for France.
Little is known about Théato, who did not work as a baker's delivery boy in Paris, as often said, but was a cabinet-maker and member of the St-Mandé athletic club. He won the race, then measured at 40,260 m and held under very hot circumstances, in just under three hours. However, his victory was not undisputed, as several runners, notably American Arthur Newton, claimed that Théato had taken shortcuts, helped by his knowledge of the Parisian streets through his alleged occupation. These assertions have been totally disproved by Olympic historians including André Drevin and Raymond Pointu (Les Marathons Olympiques, Calmann-Lévy 2003).
For a long while, it was assumed that Théato was French, and only in the late 20th century it was discovered (by Alain Bouillé) that he was born in Luxembourg. Whilst that makes him the first Olympic medallist (and one of only two, along with Josy Barthel, ever) from the country, the International Olympic Committee contends that he competed for France, and, hence, the medal is always credited to the French.