Kerttu Niskanen established herself as a formidable talent in cross-country skiing, securing gold medals at the U23 World Championships in 2010 (10 km classical) and 2011 (Individual sprint). These achievements followed earlier recognition with junior bronze medals in the 4 × 3.33 km relay at the Junior World Championships in 2007 and 2008, and an Individual sprint bronze at the U23 World Championships in 2009. Niskanen made her senior World Championship debut at the FIS Nordic World Ski Championships 2011 in Oslo, where she finished eighth in the 10 km classical event. Her Olympic career commenced at the Sochi 2014 Winter Olympics, earning two silver medals for Finland as part of the 4 × 5 km relay and the team sprint, in addition to placing fourth in the 30 km freestyle.
She secured further World Cup victories in the 10 km Individual C event in Toblach, Italy (2023) and Falun, Sweden (2023). In 2024, Niskanen continued to demonstrate her elite performance by securing a World Cup 20 km Pursuit C victory in Davos, Switzerland, followed by another dominant 10 km Individual C victory in Falun, Sweden. As a decorated Finnish cross-country skier and four-time Olympic medalist, Niskanen consistently proves her position as a leading competitor, recognized for her exceptional endurance and high-level competitive performance on the international circuit.