Super Bowl LVI MVP voters got it wrong -- Aaron Donald should've gotten the honor, not Cooper Kupp ... so says Calais Campbell.
The NFL star was adamant about it while leaving SoFi Stadium on Sunday night ... telling TMZ Sports he truly believed Donald deserved the award more than Kupp.
"Cooper Kupp did a great job, he's worthy," Campbell said. "Aaron Donald played an amazing game. He should've been Super Bowl MVP."
Kupp did score the game-winning touchdown -- and he finished the night with 92 receiving yards on eight catches -- but Donald had two sacks and helped force an incompletion on Joe Burrow's final pass of the night.