It was the second time the 30-year-old Mane, who last month joined German champions Bayern Munich, has won the award.
Mane finished ahead of Egyptian forward Mohamed Salah, his former Liverpool team mate, and fellow Senegalese Edouard Mendy in the voting.
Mane converted the winning penalty in February as Senegal beat Egypt in the Cup of Nations final in Yaounde, proving the talisman as his country took a first ever African title.
Six weeks later, he struck the decisive spot-kick as Senegal again edged Egypt in a penalty shootout to win a place at the World Cup finals in Qatar.
He overshadowed Salah on both occasions, although the pair shared success with Liverpool in the FA Cup and League Cup and helped them reach the Champions League final.
He was the last winner of the award in 2019. The Confederation of African Football did not hold it over of the last two years and has now changed to recognizing accomplishments over the season rather than the calendar year.
Mane also finished ahead of Salah in the 2019 voting. Salah, 30, won the award in 2017 and 2018 with Mane second on both occasions.
"I dedicate this award to the youth of Senegal. I'm very emotional and don't have the words to express how I'm feeling," Mane told the audience at the CAF awards in Rabat after flying in from Washington DC, where he scored in a pre-season friendly for his new club on Wednesday.