
Ion Tiriac
Tiriac is one of the most obscure names on this list but he’s also one of the most successful former stars. The Romanian was a dominant tennis player during his heyday and enjoyed several victories on the ATP Tour. But most of the richest athletes make their money away from their chosen sport.

Tiriac is no exception because he took advantage of communism’s collapse in the Eastern Bloc. He started a bank and it experienced massive growth. Now he’s one of the richest men in Romania and the nation’s first sports billionaire. It’s an amazing achievement for the former star (via Fox Sports).