Nestoras Kagiavidis was born in 1992 in Athens, Greece. He began his studies in music at Peloponnesiako and Patraiko conservatories in 2003. In 2010 he continued his studies in tuba under the instruction of Georgios Rarakos in Philippos Nakas Conservatory where he received his diploma with honours as well as the second prize. He also acquired a Degree in Harmony in 2012 (Philippos Nakas Conservatory).

In 2008 and 2009 he attended brass master classes at the Department of Music Studies of the Ionian University in Corfu given by Jens Bjorn- Larsen. The masterclasses were organized by the "Melos Brass" quintet. He also attended History of Art courses in 2010 and 2011 by Evangelos Kokkoris in Athens.

He has been performing with the Athens Youth Symphony Orchestra in Athens Concert Hall since 2012. From July 2014 till 2016 he was the principal tubist of the Metropolitan Symphony Orchestra of Athens.
He has been performing with the Athens State Orchestra and the «Metallon» brass quintet since 2014.

He served his military service in the Military Band of Athens.

He performs with a WILLSON 3400 FA-5 , Eb Tuba.