Following some good outings in December, the attacker was shortlisted for the monthly honour, alongside USA full-back DeAndre Yedlin and eventual winner Jamaal Lascelles.
In the contest decided by public votes, Atsu polled 34.8 per cent to finish second.
English centre-back Lascelles, on his part, tallied a percentage of 51.7 to claim the accolade.
Yedlin, meanwhile, came third with 13.5% of the votes.
His standout fixture was the December 23 clash with West Ham United, against whom he scored and provided an assist for another goal in a dramatic 3-2 win.
Atsu currently boasts of 18 Premier League outings, involving 15 starts and two goals this campaign.
He joined Newcastle permanently in June after helping the team secure topflight promotion during a loan stint from giants Chelsea last season.