Peter Grant Hay (9 July 1879 – 29 August 1961) was an Australian brewer, landowner, pastoralist and thoroughbred racehorse breeder.
He founded the Richmond N.S.
(for Nathan System) Brewing Co.
Ltd (Carlton & United Breweries) in Melbourne Australia.
He is responsible for both the introduction of pasteurisation to Australia's dairy industry and the introduction of the Swiss Nathan System of brewing to Australia.