Reggie Jackson Jersey From Historic 539-Foot HR Hits Auction, Could Fetch $250K!

The jersey Reggie Jackson wore when he hit his famous moonshot home run during the 1971 All-Star Game has just hit the auction block ... and it can be all yours, if you've got some serious cash laying around!!

TMZ Sports has learned ... the Oakland A's vest that Reggie donned when he smashed the 539-foot HR is currently being sold at SCP Auctions, and experts say it could go for more than $250,000!!

Of course, while the price tag is hefty, the jersey is a part of MLB history ... as it played it a role in one of the longest HRs EVER recorded in baseball.

You'll recall, Jackson hit the massive blast off of Pittsburgh Pirates ace Dock Ellis in the '71 mid-summer classic ... and it went so far, announcer Curt Gowdy could hardly find it in the air!!

"That one is going, way up!" Gowdy yelled. "It is -- off the roof!? That hit the transformer up there!"

We're told the jersey has been photomatched to prove its authenticity ... and it's been given a perfect grade by authenticating experts.