Teemu Myöhänen began playing the cello at the age of nine at the Kuopio Conservatory in Finland. He subsequently studied at the University of Music, Sibelius Academy in Helsinki with Prof. Arto Noras and Prof. Martti Rousi as well as chamber music with Prof. Ralf Gothoni, where he received his cello diploma with honours and a master's degree, followed by further studies at the Cologne University of Music with Prof. Maria Kliegel as a scholarship holder of the Wihuri Foundation and the concert exam in chamber music with the Alban Berg Quartet. He received the Finnish Pro Musica Award for talented young artists.

Teemu Myöhänen has performed in Finland as a soloist with the municipal orchestras of Kuopio and Lappeenranta and has been an active chamber musician at numerous summer festivals and concert series as well as with many German orchestras as section leader and solo cellist. (e.g. with the Deutsche Kammerakademie Neuss am Rhein, the Südwestdeutsches Kammerorchester, the Kölner Kammerorchester and the Westdeutsche Sinfonia).

In addition, he has performed as a member of various chamber music ensembles in most European countries as well as in South Africa, Japan and Mexico and has participated in numerous CD productions as a member of various ensembles and orchestras (including BIS, Naxos, Capriccio, CPO, HK Coburg, Hänschel, Genuin)

Since 2014, Teemu Myöhänen is a member of the Asasello Quartet. As a cellist of this string quartet, he can regularly be heard at major festivals and concert halls in Europe and beyond. The Asasello Quartet's recordings have received numerous awards, including the German Record Critics' Award (2016, 2023), the Super Sonic Award 2016, 2023 and the Gramophone Editor's Choice (2016). Several new recordings were released in 2024 and 2025. The Asasello Quartet's recording of Dmitri Shostakovich's String Quartets 1–6 was nominated for the 2025 German Record Critics' Annual Award in the category ‘Best Chamber Music Recording of the Year’.

A pedagogue with 30 years of experience, Teemu Myöhänen has taught at the Helsinki and Kuopio conservatories and given masterclasses in Finland (Sibelius Academy, Helsinki), Germany (Hochschule für Musik, Cologne), South Africa (University of Pretoria as part of the International Music Festival of South Africa) and workshops at schools in Cologne, Bonn, Soweto (South Africa) and Mexico City. Teemu Myöhänen is co-founder and co-director of the G. F. Handel Music Academy since 2013.