Lautner, who plays werewolf Jacob Black in the hugely popular vampire flicks, flew into Sydney on a Qantas flight from LA on Saturday night.
Stewart, who plays Bella Swan, arrived at 6.30am (AEST) on Sunday.
The pair enjoyed a jet boat ride on Sydney Harbour on Sunday, before paying a visit to Featherdale Wildlife Park in the city’s west.
They saw koalas, baby crocodiles and wombats during the trip.
On Sunday evening they had dinner at Bondi Icebergs.
Both were driven around in a convoy of Cadillac Escalade SUVs amid tight security and heavy media interest.
Teen heart-throb and Twilight co-star Robert Pattinson is not with them, but fans will get a chance to meet their idols.
Stewart and Lautner are due to be grilled by fans in a Q&A session at Sydney’s Luna Park on Monday.
So-called Twi-hards lucky enough to score tickets to the event will be treated to a screening of the second Twilight movie New Moon after the Q&A.
