Despite previously leading the club to promotion and a sixth place finish, the club’s board have decided to relieve Hartley of his duties in order to avoid relegation from this season’s top flight.
Dundee currently sit in 11th place, occupying the relegation play-off spot, and are only five points above automatic relegation.
They haven’t won in the Ladbrokes Premiership since defeating Motherwell 5-1 on 25 February.
Following Saturday’s disappointing 2-0 home defeat against Hamilton Accies, the board met to discuss the manager’s future and it was agreed a change was necessary for the club to avoid the drop.
A statement on the club’s official website read: “Dundee Football Club have this afternoon relieved manager Paul Hartley of his duties.
“The club currently sit 11th in the Premiership table and the board of directors feel a change is needed ahead of five vital matches between now and the end of the season.
“Managing Director John Nelms is currently addressing the players and staff and the club will release a further update shortly.”
John Nelms was quoted in the statement saying: “I want to thank Paul for his time with the club. Unfortunately, the business we are in, sometimes change is necessary to achieve the goals we have set. I think somebody in the near future is going to get a good hard working manager.”