billionaire

/ˌbɪljəˈnɛr/

noun

A person possessing assets worth at least a billion dollars (or pounds, etc.).

Melbourne is filling with tycoons, moguls, magnates, billionaires and mere millionaires.

magnate,mogul,big businessman,baron,merchant prince,captain of industry,industrialist,financier,top executive,chief,lord,magnifico,nabob,grandee