The Paraguayan's matchwinning strike at St. James' Park was chosen ahead of seven other efforts from last month, with Chelsea's Antonio Rüdiger, James Ward-Prowse of Southampton, West Ham's Aaron Cresswell, Brighton's Enock Mwepu, Burnley's Conor Roberts, Granit Xhaka of Arsenal and Manchester City's Rodri all beaten by the Magpies man in the public vote.
The 28-year-old's terrific curling shot, assisted by April's PFA fans' player of the month nominee Bruno Guimarães, earned all three points for United as they took another step towards securing their top flight status.
It was also Almirón's first goal of the campaign, and the first time a Newcastle player has picked up the award this season.
The last United player to collect the prize was Matty Longstaff, whose winning goal against Manchester United earned him the gong in October 2019.