Saarelainen is a Finnish surname. Notable people with the surname include:
Ilmari Saarelainen (born 1944), Finnish actor Pekka Saarelainen (1868 – 1933), Finnish farmer and politician Pekka Saarelainen (born 1967), Finnish curler Sari Saarelainen (born 1981), Finnish racing cyclist Timo Saarelainen (born 1960), retired Finnish basketball player