The Dark Blues boss has been rewarded for guiding the Dees to a top-six finish and intends on continuing the Tayside’s club upward trajectory.
Hartley, who was linked with the Cardiff City vacancy earlier on in the season, says his side have unfinished business.
“We’ve been speaking over the past six months. It was a no brainer for me.
“We are building for the future here, laying down the foundations and I’m delighted to be part of that.”
“The vision is to try make the club strong, and my vision is to make the club a top 4 side. That will take time, there is alot of work to be done and we are still building the team. We’ve got alot of unfinished business.”
The club’s managing director John Niems spoke of his delight at securing Hartley for another three years.
“The Board of Directors and myself are very happy that Paul has agreed his deal.
“Paul is an integral part of our club as we build for the future.
“He has a winning mentality which breeds and attracts a winning mentality and that is very important for us as a club and showing in the results on the park.
“We are already building for next year and the future. We are happy that as we build this foundations that Paul is going to be at the helm.”