Johnny Manziel's Blonde Party Chick Lauren Hanley -- I Sell Pot

The big-breasted bombshell who partied it up with Johnny Manziel last night is smoking hot for a reason -- TMZ Sports has learned, she sells marijuana for a living.

Model Lauren Hanley recently posted a photo from her day job on Instagram, showing off some fat nugs from The Root Cellar, a weed dispensary located in Sherman Oaks ... and she really seems to like the work, writing, "Come visit me at work! Best collective in Los Angeles!"

Our weed sources tell us Lauren's only been in the pot game for roughly a month ... but she's already become one of the dispensary's best employees.

As we reported, Lauren got down with Manziel last night at an FSU event in Hollywood and left with him and another girl in a car.

#Nofilter