Susan Aho (born 5 March 1974) is a Finnish folk music singer-songwriter and a member of the band Värttinä.

Having played the accordion since she was 13, Aho joined Värttinä in 1998, replacing Riitta Kossi, and was the accordionist and a vocalist on their album Vihma.

Aho studies at the Sibelius Academy in Helsinki and is involved in a variety of other projects besides Värttinä.

For example, she was vocalist and accordionist in the Greek group Odysseia, was a member of the folk band Metsänväki, and with the Finnish accordionist Minna Luoma played Finnish gypsy songs in the group Rotunaiset.

Aho also works with the Nukketeatteri Sampo (Sampo Puppet Theatre, founded in 1977) in Helsinki; the interplay of traditional puppet theatre with music and poetry plays a big role in its work.