Nanna Koerstz Madsen (born 23 October 1994) is a Danish professional golfer.
She represented Denmark at the 2016 Summer Olympics in Rio de Janeiro, Brazil where she ended as a tied 13.
She is presently playing on the American LPGA Tour while at the same time trying to retain her membership on the Ladies European Tour (LET).
At the end of the season 2014, Madsen finished as the best European amateur player on the World Amateur Golf Ranking.
She played college golf for one semester at the University of South Carolina, winning one tournament.