Balakauskas graduated from Vilnius Pedagogical University in 1961. After his mandatory service in the Soviet Army between 1961 and 1964, he studied composition with Boris Lyatoshinsky and Myroslav Skoryk at the Kiev Conservatory until 1969. From 1992 to 1994 he was the ambassador of Lithuania to France, Spain and Portugal (resident in Paris). In 1996 he was awarded with the Lithuanian National Award, the highest artistic and cultural distinction in Lithuania. He is currently head of the Composition Department of the Lithuanian Academy of Music and Theatre. His output consists of symphonies, concertos, chamber and instrumental music.
Important works include Sonata of the Mountains inspired by the paintings of Mikalojus Konstantinas Čiurlionis (1975), Symphony No. 2 (1979), Opera Strumentale (1987) and Symphonies No. 4 (1998) and No. 5 (2001), the last two named works having been recently recorded by Naxos Records.
- Komunarų gatvė (Street of Communards), chamber opera (1977)
- Zodiakas (Zodiac), film-ballet (1984)
- Makbetas (Macbeth), ballet (1988)
- La Lointaine, chamber opera (2002)
- Symphony No. 1 (1973)
- Symphony No. 2 (1979)
- Symphony No. 3 "Ostrobothnian Symphony", for string orchestra (1989)
- Symphony No. 4 (1998), recorded by Naxos (8.557605, 2005)
- Symphony No. 5 (2001), recorded by Naxos (8.557605, 2005)
- Opera Strumentale (1987)
- Concertino for piano and string orchestra (1966)
- Ludus Modorum for cello and chamber orchestra (1972)
- Kalnų sonata (Sonata of the Mountains) for piano and orchestra (1975)
- Passio Strumentale for string quartet and orchestra (1980)
- Concerto for oboe, harpsichord and string orchestra (1981)
- Sinfonia Concertante for violin, piano and orchestra (1982)
- Concerto RK for violin and chamber orchestra (1997)
- Concerto Brio for violin and orchestra (1999)
- Capriccio for piano and orchestra (2004)
- Concerto for clarinet and string orchestra (2008)
- Seasons for 2 pianos and string orchestra (2009)
- Chamber music
- Medis ir paukštė (The Tree and the Bird) for viola and piano (1976)
- Do nata for cello or viola and tape (1982)
- Corrente for flute, viola and piano (2005)
- Duo concertante for viola and piano (2007)
- Trio concertante for flute, viola and piano (2008)
- Requiem in memoriam Stasys Lozoraitis (1995), recorded by Naxos (8.557604, 2004)
- "Osvaldas Balakauskas". Lithuanian Music Information and Publishing Centre. Retrieved 2010-02-05.
- "THE MUSIC OF OSVALDAS BALAKAUSKAS: A GENERAL APPRECIATION". Lituanus. Retrieved 2010-02-05.
- "Celebrating the 70th anniversary of composer OSVALDAS BALAKAUSKAS". Lithuanian National Philharmonic Society. 2007. Retrieved 26 October 2012.