Synodontis nummifer, known as the two spot synodontis, is a species of upside-down catfish native to the Congo Basin of Cameroon, the Democratic Republic of the Congo and the Republic of the Congo. It was first described by the Belgian-British zoologist George Albert Boulenger in 1899, based upon a holotype discovered in Léopoldville, Belgian Congo. The specific name "nummifer" comes from the Latin for "to bear a coin", which refers to the large spots on its sides.