The folks over at Screenbid are auctioning off 48 official studio audience chairs from "The Oprah Winfrey Show." It's a big deal ... the show, of course, ended in 2011 after 25 marvelous seasons and over 4,500 episodes.

The chairs -- each with its own commemorative plaque -- are practically a steal ... the asking bids are less than $100 but if rabid fans wanna drive up bids, they'd be doing so for a great cause. We're told proceeds from the auction will benefit Oprah's Leadership Academy Foundation in South Africa, which helps empower gifted girls who come from disadvantaged backgrounds.