Zac and Vanessa were first spotted together back in July, after meeting while she was working at the Byron Bay General Store café and restaurant Light Years earlier that month.
A source told Who earlier this year: “They were introduced by her boss.”
The couple were spotted holding hands and grabbing takeaway food together and were also photographed leaving a plane in Ballina following a skiing holiday in Thredbo.
"Zac met Ness earlier in the summer. They started hanging out in July and recently took a ski trip together," a source told PEOPLE in September.
"You can tell that they are having fun. She spends a lot of time at this house."
Vanessa, who has also worked as a model for for RVCA and Spell, then left her job as a waitress and moved in with the actor at his Belongil Beach home.
In August, the Baywatch star cancelled a flight back to LA after his visa was officially extended from three months to 12.
It’s only been in recent years that heartthrob Zac has started thinking about long-term love.
“I didn’t think much about settling down until recently,” he shared.
“I’m around some great relationships … I’m realising that you have to find your own happiness before you can make somebody else happy.”
Zac has had several high-profile romances, including his High School Musical co-star Vanessa Hudgens who he dated from 2006 to 2010, but the two "completely lost contact" after calling it quits.
The actor has also been romantically linked to stars including model Sami Miró and actresses Michelle Rodriguez, Lily Collins, his Baywatch co-star Alexandra Daddario and his Bad Neighbours co-star Halston Sage at the beginning of the year.