Katri Helena Kalaoja (née Koistinen; born 17 August 1945) is a Finnish singer.

Katri Helena released her first songs in 1963 and has since sold over 630,000 certified records, which makes her the second-best-selling female soloist in Finland behind Madonna and places her also among the top 20 best-selling music artists in the Finnish market.

[2] She also took part in the Sopot International Song Festival in Poland in 1969, singing "Valssi".

She had two daughters and a son with her husband Timo Kalaoja, who died of a heart attack in 1988.

His death affected her so much that she withdrew from public view and stopped performing and recording for four years.