Tapsus (more commonly referred by Thapsus) was an ancient city in what is modern day Tunisia. It's ruins still exist at Ras Dimas near Bekalta, approx. 100 km SE of Carthage. Originally founded by Phoenicians, it served as a marketplace on the coast of the province Byzacena in Africa Propria. Established near a salt lake on a point of land eighty stadia from the Island of Lopadussa. In 46 BC it was the scene of the defeat by Caesar of Metellus Pius Scipio and the Numidian King Juba with a tremendous loss of men. He exacted of the vanquished a payment of 50,000 sesterces. Their defeat marked the end of opposition to Caesar in Africa. Tapsus then became a Roman colony.

Not to be confused with the medicinal herb Verbascum thapsus.