NBA's Scottie Barnes Belts Maroon 5 Song In Cancun

Toronto Raptors star Scottie Barnes' Cancun vacation looks like a scene outta "High School Musical" ... 'cause the hooper showed off his awesome singing abilities during a karaoke session!!

The 2021 No. 4 overall pick's offseason started early after the Dinos failed to make the postseason ... but he seemed to be in great spirits nonetheless -- belting out the classic Maroon 5 hit, "This Love."

Barnes put 100% into the performance ... dancing along to the song and doing his best to hit Adam Levine's high notes.

The crowd seemed to love the show ... singing along and waving their arms like they were at a real concert.

It's nice to see Barnes in a fantastic mood -- his season ended back in March after undergoing surgery to fix his broken hand.

He was having a career-best season in every major category prior to the ailment ... averaging just shy of 20 points, 8.2 rebounds and 6 assists a game.