Koivu
Koivu is a Finnish surname meaning "birch". Notable people with the surname include:

Mikko Koivu (born 1983), Finnish professional ice hockey player, brother of Saku 
Rudolf Koivu (1890–1946), Finnish artist
Saku Koivu (born 1974), retired Finnish professional ice hockey player, brother of Mikko

See also
Kõiv, an Estonian surname of the same etymology
Kõivu, an Estonian settlement

Finnish-language surnames