The victory took 55 minutes and sends the 41-year-old Toronto native into his third mixed final in Australia after capturing titles in 2007 and 2011.
Nestor and Mladovic will face Sania Mirza and Romanian Horia Tecau in Sunday's final. The sixth-ranked Indian pair defeated the Australian duo of Jarmila Gajdosova and Matthew Ebden 2-6, 6-3 (10-2).
Nestor is bidding for his fourth mixed trophy and his second with Mladovic. They won at Wimbledon last summer after a runner-up showing at the French Open.
"Playing with Kristina is great, she's a great partner, the best I've never had," said Nestor, "I'm sure she is the best female mixed player out there.”
"I just hope we can continue it in the final. We are serving well.”
The first ended with a break. Nestor's side took an early lead in the second set with a break and raced to 5-1 lead on the way to victory.
Nestor and Mladovic recorded 17 winners and just eight unforced errors in a polished performance.
Nestor won a Melbourne mixed crown in 2007 with Elena Likhovtseva captured the title three years ago with Slovenian Katerina Srebotnik.
The Canadian veteran and Mladovic beat Miraza and Tecau at Wimbledon last summer on the way to their title together.
"They can play well, Mirza has won some mixed titles and Tecau has been a top 10 player for the last few seasons," said Nestor.