Young Thug Placed in Cuffs & Released Hours Before Grammys

Young Thug nearly didn't make it to the Grammys after he got put in cuffs just hours beforehand -- but, luckily, he didn't find himself in a jail cell come showtime.

Law enforcement sources tell TMZ ... YT and a group of guys riding in a van were pulled over early Sunday morning for a traffic violation in WeHo. We're told Young Thug and the other passengers were taken out of the car and handcuffed.

As you can see in this video, obtained by TMZ, they were lined up outside a McDonald's ... and, at one point, Thug also had his hands over his head.

Our sources tell us one of the men in the vehicle -- not Thug -- told police that he was in possession of a registered firearm, but upon further inspection ... cops found the gun wasn't registered in California, so the guy got arrested on the spot. Everyone else was cut loose.

It's a good thing YT was able to walk away from this relatively scot-free, 'cause he was part of the opening act later Sunday alongside Camila Cabello. Seeing how he's the featured artist on her song, "Havana" ... it was kinda important that he be there.

He also ended up winning his first Grammy ever for his contribution to Childish Gambino's "This Is America," which won Song of the Year. YT was one of many MCs who provided backing vocals for the track.