Nikos Haliassas was born in Athens in 1968. He studied violin at the Athens Conservatory under Tatsis Apostolidis and in 1989 he received his degree in violin with Award and Distinction. He continued his studies with Howard Davis at the Royal Academy of Music, with Grigori Zhislin at the Royal College of Music in London as well as conducting classes by Bernard Keefe and by J. Forster. He pursued post-graduate studies in orchestral conducting at the Trinity College of Music under Peter Stark where he graduated in 1999. He has attended master classes by Jorma Panula and Alexander Mirat. For his post-graduate studies, he was granted a scholarship by the Onassis Foundation.
As a solo violinist, he has performed with the Athens and Thessaloniki National Orchestras, with the Athens Conservatory Student Orchestra and the Royal College of Music string ensemble and in several venues in Greece, England, Holland and has recorded for the Greek Radio and Television. He was a member of the European Union Youth Orchestra. Since 2001 he is a permanent member of the Athens State Orchestra, as a principal violinist.
Since 2000, he has been the founder and music director of the Intrarti Orchestra which was subsidised by European Union funds for two years and has performed numerous concerts all over Greece in partnership with leading soloists such as Dimitris Sgouros, Tatsis Apostolidis, Giorgos Demertzis, Sergiu Nastasa, George Petrou and Jenny Drivala, and with the renown stage director Michael Hampe. Nikos Haliassas has conducted the Athens State Orchestra, the Thessaloniki State Symphony Orchestra, the Thüringen Sinfoniker, the Cyprus Symphony Orchestra, the Astana Symphony Orchestra of Kazakhstan, the Greek Radio Symphony Orchestra (ERT), the City of Athens Symphony Orchestra, the City of Thessaloniki Symphony Orchestra, the Swedish Musica Vitae Orchestra and other ensembles.
He has been the music director of one of the four orchestras founded by the Greek Ministry of Education, having delivered dozens of educational presentations and concerts in primary schools in West Attica during the years 2001 to 2004. Since September 2012, he has been the artistic director of the “Sinfonia” International Festival of Piraeus and the Saronic islands which is funded by the NSRF.