Leeds, three-times English champions, lie 10th in the second-tier standings and have not recorded a league win since Dec. 26.
"Leeds United can confirm that head coach Thomas Christiansen has left the club," the club said in a statement.
"Chairman Andrea Radrizzani and the Board of Directors would like to thank Thomas and his staff for their hard work over the past eight months."
The 44-year-old Christiansen formerly managed Cypriot side APOEL.
Leeds, relegated from the Premier League in 2004, are looking for their seventh manager since 2014 and British media reported that former England boss Steve McClaren was among the favourites to get the job.
(Reporting by Ed Osmond, editing by Clare Fallon)
