The world number three made light work of Navarro in progressing to the decider, where she will meet Elina Svitolina on Sunday.
"Definitely a good start to my 2024, Emma's an incredible player," Gauff said.
"(I wanted to be) aggressive in my serve and return; we played a practice set here before the tournament started and she was playing really well so I knew I had to be at my best if I wanted to win."
Gauff made a commanding start and held a 4-2 lead in the opening set when rain, which has fallen regularly throughout the tournament, briefly stopped play.
The 19-year-old American continued her strong showing, extending her lead upon the players' return to the court and eventually winning the first set with few concerns.
Gauff then tightened her grip when she broke her compatriot's serve in the opening game of the second set and consolidated that lead further after a Navarro miss-hit in the fifth game that gave her an unassailable lead.
Svitolina managed a lower back issue and rallied from a set down to beat China's Wang Xiyu 2-6, 6-4, 6-3.
At the Brisbane International, world number four Elena Rybakina downed Czech teen Linda Noskova 6-3, 6-2 to reach the final, where she could face Australian Open champion Aryna Sabalenka in a rematch of their Melbourne Park title clash.
The second-ranked Sabalenka plays fellow Belarusian and double Brisbane champion Victoria Azarenka in the other semi-final later.
"I'll watch a bit of their match and try to do my best tomorrow," said Rybakina, who reached her 15th career singles final and fourth in Australia.
"Hopefully it's going to be a great battle."
Top seed Holger Rune overcame Roman Safiullin 6-4, 7-6(0) in the semi-finals of the men's draw and takes on the winner of the clash between Jordan Thompson and Grigor Dimitrov.
"I think I did well to be honest. When he was hitting hard I was there with some good counter-punches," said the 20-year-old Rune, who reached his ninth tour-level final.
"I managed to close it out in two sets, which is good for the energy. I'm playing better tennis every day and physically I'm feeling great, so I'm happy."
