Fernandes claimed 45 per cent of the votes cast by the English football media, beating Rice by just 28 votes.
Manchester City forward and 2023 winner Erling Haaland came third, while Arsenal's David Raya, Bukayo Saka and Gabriel Magalhaes all gained a large number of votes.
Fernandes now becomes the first United player since Wayne Rooney in 2010 to win the prestigious FWA award.
The Red Devils captain has scored eight goals and provided 20 assists in 34 appearances across all competitions, playing a major role in the club’s improvement under interim manager Michael Carrick.
Fernandes has registered 19 Premier League assists this season, just one short of the record shared by Thierry Henry and Kevin De Bruyne.
According to Opta, the Portuguese midfielder has created 120 chances this campaign, the highest total of his United career so far.
Despite the Red Devils being set to finish without a trophy again, they remain on course for a third-place Premier League finish and Champions League qualification.