Prince Jackson Nailed with Speeding Ticket

Prince Jackson picked up something in his pickup Wednesday -- a speeding ticket.

TMZ has learned ... Michael Jackson's eldest son was nabbed by cops near his Calabasas home for going around 40 mph in a 25 zone.

FUN FACT: Prince was stopped in the area where Justin Bieber and his Lil friends race his Ferrari -- at much higher speeds. FYI -- Justin and the Lils have never gotten a speeding ticket in that area.

As for Prince -- well, the 16-year-old must now dig deep, because the fine is around $250.

Already blowing the $10 billion nest egg he's after ... kids.