Nicolai Kornum Geertsen (Danish pronunciation: [ˈke̝ɐ̯ˀtsn̩]; born 19 June 1991) is a Danish professional footballer who plays for Helsingør as a defender. A versatile and opportunistic defender, Geertsen has played at different levels in both Denmark and Norway. He has captained Sandnes Ulf and Lyngby.