Travis Kelce did NOT host a big shindig in Sin City a couple nights before the Super Bowl, despite his name being on the invitation for a house party ... TMZ has learned.

There was an invite going around social media Thursday promoting "The Kelce House Party" later that night in Las Vegas ... with Travis' name prominently displayed above the RSVP. Of course, many quickly wondered ... is TK partying his off just a few nights before the game???

Understandable -- on its face, the invite made it seem like Travis was hosting the party with his brother, Jason, which was billed as an event for their 'New Heights' podcast ... and there were even some reports going around claiming Travis was hosting this thing.

However, sources with direct knowledge tell TMZ … Travis didn't host any parties in Vegas last night, and more importantly ... he isn't hosting any ahead of Super Bowl LVIII, period.

For the non-sports fans out there thinking the players on the Super Bowl teams will be having fun in and around The Strip before Sunday's Big Game, our sources say that's just not the case ... and players are basically having zero fun in Sin City before the SB.

Thing is ... we're told Travis and the Kansas City Chiefs players have some pretty loaded schedules, plus a curfew. They start their days early and the day is filled with meetings, practices and training.

They have a strict curfew at midnight every night ... and our sources say if Travis or any of the players get caught anywhere near The Strip, they aren't going to be playing in the Super Bowl.

By the way, the Chiefs are staying far away from the glitz and glamour ... the team hotel is The Westin Lake Las Vegas Resort & Spa, about a 40-minute drive from The Strip.

Sounds like Travis missed out on a fun party with his brother ... the invite says, "You're invited to come through the Kelce House, grab a beer (or 20, alright nah), kick back in the living room, take in an electric set from Cleveland's own DJ MEEL, play some pong on the deck, and all that. Be cool, have a good time, and above all - DON'T tell mom!"

Now, on the question of whether this 'Kelce House Party' is legit -- our sources tell us it is ... but that Travis himself was never explicitly tied to it. It was basically a bash put together by people who help run his podcast ... and we're told upwards of 400 individuals got an invite.

Unclear if Jason showed up or not -- he's a cohost of 'New Heights,' after all -- but we know for a fact ... Trav was nowhere near this thing on Thursday.