Leeds haven't played in the Premier League since being relegated after the 2003-04 season.
https://www.bbc.com/sport/football/44236885
Which is patently ridiculous when you consider their level of support and their history. Leeds were always able to find a way back from their down cycles until the aftermath of their insane financial mismanagement in the late 90s. They picked a bad time to get bad ... right as the money was getting so big at the top, making it much harder and more expensive to advance.