Mooy has been impressive for Huddersfield in the Premier League this season and played a key role in helping the Australian national team secure qualification for the 2018 World Cup.
Kagawa, who won the award in 2012, earned his nomination as a result of his heroics for the Japan national team and Borussia Dortmund.
Meanwhile, Son is a key player for South Korea and is also impressive when called upon by Tottenham.
Australian national team coach Ange Postecoglou, who has yet to decide whether he will remain in charge of the Socceroo's ahead of the 2018 World Cup, is also a nominee for Coach of the Year.
Postecoglou earned himself a nomination along with the Japanese duo of Ishii Masatada, who coaches Kashima Antlers, and Takafumi Hori, who coaches Urawa Red Diamonds.