Oskar Merikanto (pronounced [ˈoskɑr ˈmeriˌkɑnto] (listen); born Frans Oskar Ala-Kanto; 5 August 1868, Helsinki – 17 February 1924, Hausjärvi-Oitti) was a Finnish composer, music critic, pianist, and organist.

As a composer, Merikanto was primarily a miniaturist, and his extensive œuvre includes songs and piano pieces (he wrote over 100 of each). Of the latter, he is best remembered for: Summer Evening Waltz (Kesällan valssi, Op. 1), Romance (Romanssi, Op. 12), Summer Evening Idyll (Kesällan idyll, Op. 16/2), Valse lente (Op. 33), and Idyll (Op. 73/1). Merikanto also wrote three operas: The Maiden of the North (Pohjan neiti, 1898), which retains a degree of historical significance as the first opera composed to a Finnish libretto; The Death of Elina (Elinan surma, 1910); and Regina von Emmeritz (1920). However, Merikanto's operas have entered neither the domestic nor the international repertoires.

As a music critic, Merikanto was associated with the Finnish-language, liberal, nationalist newspaper Päivälehti.