The hat carried an estimate of €30,000-40,000 and auction house De Baecque et Associés said there are records confirming it was taken by a Dutch captain as a war trophy after the battle of Waterloo in 1815.
It has been purchased by a collector.
Although there is no concrete proof it ever belonged to Napoleon, auctioneer Etienne De Baecque told Agence France-Presse: "There are some distinctive elements: Napoleon hated the internal band so he always had it removed.”
"Historical souvenir craze"
De Baecque added that there is "a sort of craze going on with historical souvenirs, in particular those from Napoleon".
Experts believe the French emperor had around 120 hats during his 15 years in power and most were made by the French hatmaker Poupard in black felted beaver fur, though only a handful of confirmed examples exist.
The hat was sold with its box used for its display at the World Expo in Brussels in 1897. It had passed down through the captain's family until the end of the last century, when it was sold to a French collector.
Demand for Napoleon-related items shows no sign of decreasing.
However, the €280,000 paid in this auction is far less than the €1.5m (£1.25m) paid for a Napoleon bicorne in 2014.
Last year a gold laurel leaf from the crown made for Napoleon's coronation in 1804 sold for a hammer price of €500,000 (£443,193).
