The German Cup winners have appointed Dutchman Peter Bosz as the successor to Thomas Tuchel. Bosz leaves Amsterdam side Ajax after guiding the club to a Europa League final.
Peter Bosz is the new "Bosz" of Borussia Dortmund.
The Dutchman, 53, has signed a two-year contract as coach and joins from Ajax.
"Dortmund are among the biggest clubs in Europe. It is a great honor to train this club," he told a news conference at their Signal Iduna Park stadium.
"I am convinced that we can work very well together."
Dortmund made their move for Bosz after the reported rejection of overtures to French club Nice for Lucien Favre.
Media reports suggest Dortmund will have to pay around 5 million euros ($5.6 million) in compensation to Ajax for his signature.
Dortmund chief executive Hans-Joachim Watzke said: "We had a good feeling from the moment we started talking to Peter Bosz, a feeling we could grow together."
His stock has risen this year with Ajax's run to the Europa League final, which they lost to Jose Mourinho's Manchester United last month.
Throughout the competition, and domestically in the Netherlands, a youthful Ajax played fast, entertaining and attacking football that caught the attention of a host of European clubs.
The former Maccabi Tel Aviv and Vitesse Arnhem boss played briefly for Hansa Rostock in Germany and speaks the German language fluently.
Bosz's first job is to sort out the future of star striker Pierre-Emerick Aubameyang, who looks set to leave the club, with Paris St. Germain mooted as a likely destination.
Thomas Tuchel left Dortmund last week after his relationship with the club's board deteriorated. They ended the season by winning the German Cup and qualifying for the Champions League group stage by finishing third in the Bundesliga.