Gustavo Martin Emilio Hamer (born 24 June 1997) is a professional footballer who plays as an attacking midfielder for Premier League club Coventry City. Born in Brazil, he has represented the Netherlands at youth level. After moving to the Netherlands as a child, Hamer began his career at Feyenoord where he progressed through the youth system. He made two appearances for the first team before being loaned out to FC Dordrecht for the 2017–18 season.