Lotta Wennäkoski (born 1970, Helsinki) studied first violin, music theory and Hungarian folk music in the Béla Bartók Conservatory in Budapest. She then studied music theory and composition at the Sibelius Academy where her composition teachers were Eero Hämeenniemi, Kaija Saariaho and Paavo Heininen. 1998-99 Wennäkoski studied in the Netherlands with Louis Andriessen, and her debut concert took place in Musica Nova Helsinki festival in 1999.

In 2017 BBC commissioned Wennäkoski an orchestral work Flounce, which was premiered at the 2017 Last Night of the Proms. Further commissions include: string quartet, Pige, for the Danish String Quartet; the harp concerto, Sigla, for Sivan Magen; and Finnish RSO and the opera, Regine, for the Savonlinna Opera Festival. The libretto tells the story of philosopher Søren Kierkegaard's fiancé, Regine Olsen.

The Finnish Radio Symphony Orchestra recorded Wennäkoski's orchestral music in 2015 (Soie) and in 2022. She was awarded Finland's State Prize of Music in 2020.