Aldo (26-2) will open minus-130 to defend his 145-pound championship. Holloway (17-3) comes back at plus-100. The fight will headline UFC 212 inside HSBC Arena in Rio de Janeiro.
Betting lines were provided by Nick Kalikas of MMAOddsBreaker.com.
"It's going to be a competitive fight that probably hits the scorecards," Kalikas told ESPN.com. "That said, Aldo can finish anyone at any time. He's the best featherweight of all time."
Aldo, 30, has opened a betting favorite in each of his 10 UFC fights except one -- his 2015 title defense against Irish star Conor McGregor. Aldo lost that fight via 13-second knockout.
Holloway, of Waianae, Hawaii, is riding a 10-fight win streak. He won the interim belt by knocking out Anthony Pettis at UFC 206 in December and, according to Kalikas, has won the trust of the betting public.
"Holloway has been bet up to an extreme degree in his last eight fights, with the public riding him for almost all of his win streak," Kalikas said.
"Aldo is a deserving favorite based on his longtime domination, but there is obviously a lot of respect for Holloway and his run. Also, Holloway is just entering his prime, while Aldo's best years may be behind him."
The title fight will take place in Aldo's backyard, as he trains out of Nova Uniao in Rio de Janeiro. He won an interim title by defeating Frankie Edgar at UFC 200 this past July and was promoted to official champion late last year when McGregor moved up in weight and won the lightweight title.