Here's how you can get one. - by Chanelle Mansour 17 Jun 2021 McDonald’s is offering 50c Big Macs in celebration of its 50th anniversary in Australia, and not only that, but the fast food chain will be announcing a new initiative every week in winter. WATCH BELOW: McDonalds new healthy menu Australians will be able to score a 50c Big Mac on Friday 18 June, as part of a promotion as McDonald's celebrates 50 years of milestones and memories in Australia. “We are extremely proud to be celebrating 50 years of providing great tasting food and supporting our customers, people and communities in Australia,” said Andrew Gregory, CEO of McDonald’s Australia.