Aapo Häkkinen studied harpsichord with Elina Mustonen, Bob van Asperen and Pierre Hantaï, and also enjoyed the generous guidance and encouragement of Gustav Leonhardt. Immediately after obtaining his diploma in 1998, he won second prize and the VRT prize at the Bruges Harpsichord Competition. He was also awarded the Norddeutscher Rundfunk Musikpreis 1997 for his interpretations of Italian music.
Aapo Häkkinen made his debut in 2000, and has since appeared as soloist and conductor with orchestras such as Tampere Philharmonia, Tapiola Sinfonietta, Orchestra del Teatro Olimpico di Vicenza, Orquestra Metropolitana de Lisboa and Musica Aeterna in Europe, Turkey, Israel, Japan, South Korea, USA, Brazil, and Mexico. In 2002-2004 he was assistant conductor to Christophe Rousset at the opera houses in Ambronay and Leipzig. He made his debut as opera conductor with the Croatian National Opera in 2004.
Aapo Häkkinen has made several recordings for the labels Aeolus, Alba, Avie, Cantus, Deux-Elles, and Naxos. He has edited a series of music for keyboard from the 15th Century Florence for the Ut Orpheus Edition. He teaches at the Sibelius Academy and at international masterclasses. Since 2003 he has been Artistic Director of the Helsinki Baroque Orchestra, and under his leadership the orchestra has earned international fame and has frequently toured the world. The orchestra has since 2011 a concert series of its own in the Helsinki Music Hall.