Among his graduating classmates were: Helle-Reet Helenurm, Peeter Jakobi, Katrin Karisma, Enn Klooren, Kalju Komissarov, Jaan Tooming, Mari Lill, and Raivo Trass.
[4][5] In 1970, Roo made his feature film debut in the small role of Olev in the Tallinnfilm drama Valge laev, directed by Tallinn State Conservatory classmate Kalju Komissarov.
[12] In 2005, Roo appeared as Pope Innocent III in the joint ETV, Exitfilm, Õ-Fraktsioon historic comedy film Malev, directed by Kaaren Kaer.
[13] This was followed by the role of a cleric in the Rainer Sarnet directed Exitfilm drama Kuhu põgenevad hinged in 2007, based on the 2007 Aidi Vallik novel Mis sinuga juhtus, Ann?.
Some of Roo's most notable roles on television include that of Jüri Roll in the 1984 Peeter Urbla directed Eesti Televisioon (ETV) World War II television film Võõra nime all, and the recurring role of Nikifor Kessner on the ETV comedy series ENSV, which ran from 2010 until 2019 and humorously reflected on life in the 1980s during the era of the Estonian Soviet Socialist Republic.