Conor McGregor would like to apologize all you whiskey drinkers who have been dying to get their hands on his Proper 12 whiskey ... saying he's sorry for the worldwide shortage.
Proper No. 12 tells TMZ Sports they've "sold more cases in less than one month than many whiskey brands sell in a full year" ... amounting to hundreds of thousands of bottles sold.
The crazy sales have led to a shortage of the product -- great for Conor's bank account -- but bad news for fans tryin' to get their paws on a bottle.