Thodoris Rellos was born in Athens. He studied flute, music theory and byzantine music.

Since the early '80s he started playing with various groups and performing in concerts and festivals in Greece and abroad.
He is a founding member of the group Mode Plagal and has a long-time collaboration with Michalis Siganidis and Chimerinoi Kolimvites. He has also collaborated with many well known artists, such as Thanos Mikroutsikos and the groups Trypes, Fatme and Vosporos.

He has recorded for radio and TV shows as well as for theatre and dance performances and for films. His playing fuses jazz and free improvisation with traditional greek and balkan music influences.