Matthew McConaughey is NOT “alright, alright, alright” with Texas fans throwing junk on the field during Saturday’s game against Georgia … telling students to “clean that kind of BS up” and do better moving forward.

As we previously reported, UT got hit with a $250k fine for hurling bottles and debris after a controversial pass interference call in the third quarter of the matchup … which briefly delayed the action at Darrell K Royal-Texas Memorial Stadium.

The actor — who also serves as the Minister of Culture for all things UT-related — was not happy with how things unfolded … releasing a statement directed at the student body.

“But let’s get real about the bottle bombing the field glitch we had,” MM said. “Not cool. Bogey move. Yeah, that call was BS, but we’re better than that. Longhorn Nation knows how to show up, show out like no other, and still keep our class.”

MM said the fans can make up for it by keeping their trash to themselves while maintaining their passion … starting with the Longhorns’ next home game against the Florida Gators.