Tõnu Naissoo was born in Tallinn. He is the son of composer Uno Naissoo. He began studying classical piano at the age of six at the Tallinn Music School, graduating in 1970 with a degree in music theory. In 1982 he graduated from the Tallinn State Conservatory in composition under instruction from Eino Tamberg.
He has played on several musical groups, including Tõnu Naissoo Trio, Optimistid (1967–1968), Collage (1967–1972), Sinilind (1971–1972), Laine (1972–1976), Synthesis (1977–1980), Kaseke (1980–1981). About 30 years he has been a pianist in the Viru Hotel.
He has written music for films and theatrical stages.
- "Naissoo, Tõnu | Estonian Music Information Centre". www.emic.ee. Retrieved 17 May 2021.
- "Teenetemärkide kavalerid: Tõnu Naissoo". www.president.ee. Retrieved 17 May 2021.