Wrestler Jeff Hardy -- Begins 10 Day Jail Sentence for Drug Conviction

Former wrestling star Jeff Hardy has checked into a North Carolina jail to serve his 10-day sentence stemming from a drug arrest back in 2009 ... TMZ has learned.

Hardy was arrested on Sept. 11, 2009 after cops say they found all sorts of drugs in his home -- including opium and cocaine.

Hardy struck a deal with prosecutors ... in which he agreed to plead guilty to two counts of possession of a controlled substance and one count of conspiracy to traffic in exchange for a 10 day jail sentence, 30 months of probation and a $100k fine.

34-year-old Hardy -- who took a brand new mug shot upon arrival to the jail -- was listed at 6'1" and 215 lbs.