The Reds keeper, currently away on international duty with Cameroon, received the accolade for his astounding double stop during the goalless draw at Crystal Palace last month.
After pushing away Eddie Nketiah's drive, Onana reacted quickly to deny Ismaila Sarr from the rebound, when a goal seemed certain for the Eagles.
It was a key moment in the game and former United no.1 Peter Schmeichel offered his expert opinion on the save to the Premier League's official website.
"You don't expect it to go through him [Matthijs de Ligt]," said the Dane.