Throw Justin Timberlake's name in the hat to play Rafiki in the live-action 'Lion King' flick -- 'cause he executed the Simba lift on a baby to perfection at a golf tourney ... and TMZ Sports has the video. 

JT and Steph Curry were in between holes at the American Century Celebrity Golf Championship in Tahoe this weekend -- when a new dad (who happens to be a military vet) asked the guys to take a pic with his kid!

Timberlake obliged and held up the baby for all to see ... while Steph busted out the "Circle of Life" intro.

Speaking of 'Lion King,' Donald Glover is playing Simba in the new movie ... how awesome is that?!