Deontay Wilder says he’ll slap Jarrell Miller on sight for running his mouth … telling TMZ Sports he hopes “Big Baby” has his funeral arrangements made — ’cause he’s a dead man walking!!

Miller (26-1, 22 KOs) has been calling out the former heavyweight champ for a minute … claiming he’ll whoop his ass if they ever agree to a fight.

So, when we spotted the Bronze Bomber at LAX this week … we had to ask for his response — and he says he doesn’t need to be in a boxing ring to get his hands on the guy.

“If I saw him today, I’d slap the f*** out of him right now. I ain’t playing around with nobody. Deontay Wilder has returned fully, and everybody will respect the name.”

Wilder (43-4, 42 KOs) will have to get through Tyrrell Anthony Herndon on June 27 before he shifts his focus to Miller … which marks his first match since his TKO loss to Zhilei Zhang last year.

Wilder said he’s taking the match personally and seriously … despite the critics calling it nothing more than a tune-up.

“This is just the return of me,” Wilder said. “I’m coming for all the belts in the heavyweight division.”

Wilder is clearly out for revenge … and said he has more possible fights lined up for this year — though whether Miller will be included in his plans remains uncertain.