Jamie Foxx was FEEEEEEEEEELLLLIIINNNN' himself after the Cowboys beat the Saints ... 'cause dude broke out ALL his Dallas jerseys and had a dance party in his living room!!
The 'Boys scored a massive win over New Orleans on Thursday night in a game nobody predicted them to win ... and Foxx turned up like they just earned the Lombardi Trophy.
Jamie -- rockin' an Emmitt Smith throwback -- threw down some epic dance moves to "We Dem Boyz" ... and then started the trash talk.
"I told y'all!