Sean O'Malley was scheduled to fight Louis Smolka at UFC 264 on July 10 in Las Vegas, but Smolka had to withdraw Monday because of a staph infection, Smolka's manager, Jason House of Iridium Sports, told ESPN.
Moutinho will be making his UFC debut.
Chartier said Moutinho is "an aggressive striker with a solid wrestling base" who has a "very fan-friendly style."
O'Malley vs. Smolka was planned to kick off the UFC 264 main card. The pay-per-view event will be headlined by the trilogy fight between former two-division champion Conor McGregor and top lightweight Dustin Poirier.
Smolka (17-7), a 29-year-old Hawaii native, has won three of five during his second stint in the UFC, which began in 2018.