Both are widebody planes which are popular with passengers on the route where narrow body, single aisle planes provide a high proportion of the 10 million seats available each year.
Dreamliners entered the Qantas fleet from October 2017. The airline has eight of the planes and six more will arrive from October this year ahead of the retirement of the last of its Boeing 747s in 2020.
Qantas International acting chief executive Naren Kumar said the debut of the Dreamliner across the Tasman was good news for customers, while also making the best use of the airline's fleet.
"The Dreamliner has been incredibly popular so we're pleased to give our customers travelling between Auckland and Sydney the opportunity to experience it," he said.
The aircraft has 42 business, 28 premium economy and 166 economy seats.
Qantas has on sale seats in premium economy from $299 one-way for QF141 and QF144 between Auckland and Sydney.
Qantas Dreamliners are powered by General Electric engines. Its Perth-London flights are the longest flown by Dreamliners, a flight of 14,499km. It is the first scheduled flight linking Australia and Britain.