Sky Sports understands the Magpies have finally reached an agreement with the Ligue 1 side on a six million euros transfer after failing to land the player despite protracted talks during the summer.
The 27-year-old will sign when the transfer window opens on Tuesday, and that would come as a timely boost for Pardew after a difficult festive programme.
The 51-year-old side saw his team score three times at Manchester United on Boxing Day and on a further three occasions at Arsenal on Saturday, yet leave empty-handed having conceded a total of 11 times.
Newcastle's lack of depth has been cruelly exposed by injuries and suspensions in recent weeks.
Debuchy's addition to the squad would put a player of international quality at Pardew's disposal.
He appeared in all four of his country's games at the Euro 2012 finals in Poland and Ukraine last summer and now has 13 senior caps to his name.
Should the Magpies push home their interest in Debuchy, he is unlikely to be their last defensive target and they retain an interest in FC Twente's Douglas, a man they also chased last summer.