Nicolaas Jan Dirk "Nico" Nagelkerke (born 1951) is a retired Dutch biostatistician and epidemiologist. He was a professor of biostatistics at the United Arab Emirates University and previously taught at the University of Leiden in the Netherlands.
In 1991, he defined the Nagelkerke R-squared, an equation adjusting the Cox and Snell R-squared value to be comparable to the traditional coefficient of determination.