The often-outspoken former Chelsea chairman bought Leeds in January 2005 and held power at the club until signing over to current owners GFH Capital in December last year.
Bates remained as chairman until June 30 when he started a three-year term as president, but that was abruptly ended on Friday night.
A short statement from managing director David Haigh read: "Ken Bates has ceased to be president of Leeds United Football Club. Mr Bates will now no longer have any role within the football club."
The news is sure to please a number of Leeds' fans who spent long periods of his reign protesting at a perceived lack of investment. Leeds entered administration under his stewardship in 2007 and had to start a season in League One with a starting points tally of minus 15.
It remains to be seen whether Bates, now 81, will return to football in any capacity. He famously bought Chelsea for £1 before selling out to current owner Roman Abramovich in 2003.