Green Bay Packers superstar Za'Darius Smith admitted to cops he had smoked weed shortly before he was pulled over for speeding ... telling an officer, "We had smoked earlier."
It's all in police video obtained by TMZ Sports ... which shows Smith and Packers rookies Rashan Gary and Kingsley Keke getting stopped on Sept. 29 in Racine, Wisc.
Smith was busted for doing 81 mph in a 60 -- but when a cop asked him how much weed he had in his vehicle ... the superstar pass rusher straight-up admitted to smoking earlier in the day.
That's when the officer put Smith and his teammates in cuffs and searched the 2019 Yukon ... and found what appeared to be blunts and a vaping cartridge in the guys' pricey bags.
When the cops came back to ask who owned the blunts ... Smith seemed surprised to learn they were in there -- but took the fall for them anyway.
"I'll put it on me, yessir," Smith said.
As for the cartridge, Smith also took the fall for that, saying again, "I'll put that on me."
The cop cited Smith for speeding and possession of marijuana. Gary and Keke were NOT cited in the incident.
Unclear if the NFL will hand down punishment to Smith for admitting to smoking ... but it'd be a big deal if they did. Za'Darius has been a star for the Packers after signing a 4-year, $66 MILLION deal this offseason.
As for his citations ... Smith's facing nothing more than fines for those, but his attorney entered a not guilty plea on his behalf to both of the infractions earlier this week.
Smith -- who's on track to be a Pro Bowler this season -- is due in court for another hearing on the matter next month.