Aino-Kaisa Saarinen (born February 1, 1979 in Hollola, Päijänne Tavastia) is a Finnish cross country skier who has competed since 1998. Competing in two Winter Olympics, she won three bronze medals with one in 2006 (Team sprint) and two in 2010 (30 km, 4 x 5 km).
Saarinen also won six medals at the FIS Nordic World Ski Championships with four golds (Team sprint: 2009, 10 km: 2009, 4 x 5 km: 2007, 2009) and two bronzes (7.5 km + 7.5 km double pursuit: 2009, 10 km: 2011). She has six individual victories in FIS races since 2002, but did not win her first World Cup event until she won the 30 km classical event at the Holmenkollen ski festival on March 17, 2007.
Saarinen finished second in the 2008/2009 Tour De Ski behind Virpi Kuitunen.