Nicolaas "Nico" Hessel Rienks (born 1 February 1962) is a former rower from the Netherlands and two-time Olympic gold medallist.
Rienks won the gold medal in the men's double sculls at the 1988 Summer Olympics, alongside Ronald Florijn. At the 1996 Summer Olympics, he repeated his gold medal performance winning the eight with coxswain event with the Holland Acht (Holland Eight). He also competed at the 1984 and 2000 Olympics but finished outside the podium.
With Henk-Jan Zwolle he won the gold medal in the double sculls competition at the 1991 World Rowing Championships. He also won three silver medals at the world championships in 1989 (double sculls), 1994 and 1995 (eights).