The title of the richest former professional tennis player of all time belongs to Ion Țiriac, the Romanian entrepreneur and former Davis Cup player whose massive fortune is estimated by financial publications to exceed two billion dollars. Unlike modern tennis superstars whose wealth stems primarily from tournament prize money and luxury sports endorsements, Țiriac built his immense empire through post-retirement business ventures spanning international banking, insurance, real estate development, and automotive retail networks. Among modern players who earned their fortunes directly through tennis and unprecedented global branding, legends like Roger Federer have also crossed the billion-dollar threshold, but Țiriac remains comfortably at the top of the all-time financial hierarchy due to his extensive commercial conglomerates.