Instead of the regular beef, the new Chicken Big Mac features crispy chicken patties, with lettuce, onions, cheese, pickles and McDonald's Big Mac sauce.
As for the Bacon Big Mac, it will include two rashers of bacon within McDonald's regular beef Big Mac.
And that's not all, as along with the new Big Macs, McDonald's is also bringing back its popular Onion Rings with BBQ sauce - a fan favourite across Australia.
Speaking on the new launch, McDonald's Australia Marketing Director Tim Kenward said Macca's is excited to release the new summer menu items.
"Macca's is an iconic part of Aussie Summer," Tim said.
"Whether you’re on the road, at the beach, or watching sport, Macca's can help customers enjoy great times together by providing delicious flavour combinations you can’t get anywhere else.
"We're delighted to be bringing back some Aussie favourites, alongside new menu items, giving Aussies more of what they crave this summer."
The new menu items come right off the back of McDonald's new Tim Tam McFlurry, which is now available at restaurants nationwide, a week after it first launched on Uber Eats.
The one-of-a-kind dessert features velvety soft serve with crunchy biscuit pieces and a smooth milk chocolate sauce.
The launch marks the start of what Macca's is calling its biggest summer campaign yet, with new flavour combinations, menu items and collaborations hitting restaurants from now until February.