Timothée Chalamet's wish to play Ernie Johnson in a biopic might come true ... 'cause the actor just got a big thumbs up from the "Inside the NBA" host himself!!

Timmy C -- who portrays Bob Dylan in the new "A Complete Unknown" movie -- recently revealed he'd be down to honor the longtime sports TV show host on the big screen ... if he were to ever take on another biopic.

E.J. got wind of Chalamet's comments on Thursday ... and he said the "Dune" star gave him a ton of cred with his family.

"I can't believe Timothée Chalamet said that, but it made me a hero with my kids and grandkids."

Johnson also had a hilarious reaction to his wife's cameo appearance during the segment ... in which she claimed he wanted to check out the new Dylan flick to do his research on Chalamet -- although he denied that notion and said it was due to his love for the songwriter.

Charles Barkley wasn't too happy about it -- pointing out how Chalamet also shouted out Kenny "The Jet" Smith for inspiring his fashion sense not too long ago as well ... and to him, it's all "getting out of hand."

But, Johnson?? He's all in ... telling Chalamet to "call me, let's talk about it!!"