Tanguy Gérald Cosyns (born 29 June 1991) is a Belgian professional field hockey player who plays as a forward for Racing Club de Bruxelles and the Belgium national team.

His first selection in a competition was for the Men's FIH Hockey World League Round 2 hosted by Saint Germain HC.

His first major event was the 2014 Men's Hockey World Cup in The Hague where he finished in 5th place, scoring 5 goals.

He was part of the Belgian men's team that won the silver medal at 2016 Summer Olympics in Rio de Janeiro scoring 5 goals.

In August 2024 he announced after the victory 4–1 in the 2023–24 FIH Pro League against Spain in Antwerp would be his last match with the national team.