Harouna Sy (born 30 March 1996) is a French professional footballer who plays as a left-back.
On 29 July 2021, Sy joined Amiens on a two-year contract.
On 13 January 2023, Sy signed for Greek Super League side Volos. On 18 May, the club announced that Sy's contract had been terminated by mutual agreement.
On 28 August 2023, Primeira Liga side Estoril announced the signing of Sy on a one-year contract.
On 28 January 2025, after over six months as a free agent, Sy joined Championnat National 3 club C'Chartres.
Harouna Sy was born in Normandy. He holds French and Senegalese nationalities and is of Mauritanian descent.