The Whites are currently second from bottom of the Championship with just two wins and a draw from eight games and have scored only four league goals in the process.
A statement from the club read: "The board of Leeds United have today terminated the contract of manager Kevin Blackwell. The club would like to place on record its thanks to Kevin for the work he has put in over the past three-and-a-half years, the past two and a half of which were as manager.
"No further comment will be made at this time."