The spectacular effort, which came in Black Sea Storm’s 4-2 victory, had earlier been voted Goal of the Month and beat strikes from Fenerbahce’s Marco Asensio and Beikta star Orkun Kokcu to claim the top honour.
The award caps a remarkable debut season for the Nigerian forward, who joined Trabzonspor from Southampton last summer.
Onuachu finished as the Turkish Super Lig’s joint-top scorer with 22 goals, sharing the Golden Boot with İstanbul Basksehir’s Eldor Shomurodov.
The 31-year-old registered 26 goals and two assists in 43 appearances across all competitions, playing a pivotal role in Trabzonspor’s success.
He also scored both goals in the Turkish Cup final as the Black Sea Storm defeated Konyaspor 2-1 to lift the trophy for a record-extending 10th time.