Big Mixu Makes Hibs Return
The former Finland international moves to Scotland from Finnish Premier League side FC TPS Turku, who he guided to third place last season, and he will be presented at a 4pm press conference in Edinburgh on Thursday.
Paatelainen said of his new appointment, "I am very happy to take up this opportunity."
"Everyone knows of my great affection for this club, and I believe my desire to see teams play exciting, attacking and intelligent football fits well with the club's philosophy.
"I will bring energy, hard-work and leadership to the squad. I am also committed to working with players, as individuals and groups, to help them to improve.
"If I can help one player improve, the team is better. If I can help all players improve, we are much better."