Moniek Nijhuis (born 20 March 1988) is a Dutch swimmer who specializes in breaststroke. After she had been a professional swimmer, under the guidance of Martin Truijens, for several years she took a break from professional swimming after she had missed out for the 2008 Summer Olympics. She wanted to concentrate more on her study and train less. She still swims at De Dolfijn swimming club in Amsterdam.
Nijhuis competed at the 2008 European Aquatics Championships in Eindhoven in her homecountry. She failed to qualify for the 2008 Summer Olympics when she performed disappointingly in the 100 m breaststroke. In the 50 m breaststroke she ended 6th in the final after she swam a national record in the semifinal. A few weeks after this championships Nijhuis announced that she would make a step back in her career focusing more on her study and put less hours in her swimming career.
Nijhuis broke the national record in the 50 m and 100 m breaststroke (SC) in Aachen at an early season meet. At the Swim Cup Eindhoven 2008 she lowerd the national record in the 50 m breaststroke (LC). The week afterwards she took part in the European Short Course Swimming Championships 2008 in Rijeka, Croatia. There she won her first individual medal, bronze, in the 50 m breaststroke and also reached a 6th place in the 100 m breaststroke, in both events she lowered her own national record. In the 4×50 m medley she won a gold medal alongside Ranomi Kromowidjojo, Hinkelien Schreuder and Marleen Veldhuis equalling the world record that was set by Australia.