Reggie Bush Praises USC Star Caleb Williams, Calls QB's Ceiling Limitless

Reggie Bush is such a huge fan of USC quarterback Caleb Williams ... he tells TMZ Sports he thinks there's absolutely no ceiling on what the signal-caller can do with a football in his hands.

"He's a great young kid," Bush told us out at Dash Radio in Los Angeles this week. "The sky is the limit for him."

Of course, Bush would know a thing or two about the topic ... he balled out at SC from 2003 to 2005 -- and then went on to have a solid 11-year NFL career.

Clearly, he believes Williams can do the same -- and even more -- telling us he's stoked to see what the 21-year-old can do following his Heisman Trophy campaign last season.

Bush says he's actually spoken to Williams in person before ... and called their meet-ups "amazing."

As for when Williams -- who transferred from Oklahoma to USC prior to last season -- eventually gets to the pros ... Bush said there isn't one team in the league that should pass on him in the 2024 NFL Draft.

"Anybody can use him!"