Maano Männi studied the violin at the Estonian Music Academy under the guidance of professor Jüri Gerretz in 1985-1992. Männi worked as leader of the Tallinn Chamber Orchestra in 1993-1996, and as first leader in the Estonian National Symphony Orchestra in 1993-2000. Since 2002, Männi has been alternating leader of  the Vaasa City Orchestra, and in 2004-2005 he was visiting leader at the Estonia Theatre. He has performed as chamber musician for instance with the Nyyd Ensemble, Nobel Quartet, Camerata Nordica (SE), and at the Korsholm Music Festival. He has appeared as soloist with conductors such as Neeme Järvi, Alexander Vedernikov, Andrey Boreyko, Arvo Volmer, Juha Kangas, and Jin Wang.

Maano Männi has participated in conducting classes with Jorma Panula and Leonid Grin, and has studied privately with Ilmar Tõnisson. He has conducted the Vaasa and Pärnu City Orchestras, as well as the Klaaspärlimäng Sinfonietta (Glasperlenspiel Sinfonietta Tallinn). 

Since January 2016, Männi has been playing on a Charles François Gandi violin built in 1810 and owned by the Finnish Cultural Foundation.