General manager Lou Lamoriello released a brief statement saying there will be no further comment until after he addresses the team on Saturday.
DeBoer's dismissal comes as the Devils (12-17-7) sit seventh in the NHL Eastern Conference Metropolitan Division, having lost seven of their past eight games.
The 46-year-old, who finished his Devils tenure with a 114-93-41 record, was hired in July 2011 after replacing Jacques Lemaire.
DeBoer's 114 wins ranks second only behind former Devils coach Lemaire (276).
He guided the Devils to the Stanley Cup Final in 2012 but failed to take the team back to the post-season since that 4-2 series loss to the Los Angeles Kings.
DeBoer is the third NHL coach to be sacked this season following the dismissals of Paul MacLean (Ottawa Senators) and Dallas Eakins (Edmonton Oilers).