The 17-year-old’s second strike in our Under-18s' Youth Cup final triumph also featured on the eight-goal shortlist, as did team-mate Rhys Bennett’s header from the same fixture.
The award adds to what has been a mightily impressive May for Garnacho, who was named United Under-18s’ Player of the Year before the final at Old Trafford.
The youngster beat off competition from Bruno Fernandes, Raphael Varane, Leah Galton, Martha Thomas, and Bennett to receive the award, with all five having also scored standout goals in the month.
By winning May's prize, Garnacho breaks Cristiano Ronaldo’s streak, with the Portuguese having won the accolade in each of the previous three months.