Tassos Mantzavinos was born in Athens in 1958. He took his first painting lessons with Manos Sofianos and Mimis Kontos. He studied painting at the Athens School of Fine Arts (1979-1984) and graduated with honors. Alongside his artistic career, he taught drawing at the Vakalo Art & Design College (1986-2000) and worked as a book illustrator.

The main characteristics of his painting, which are already apparent in the early stages of his career, are the anti-naturalistic expressionist sharpness of forms and the existential exploration through peculiar subjects, but also through the very act of painting itself. In most of his work, especially after the mid-1990s, narrative elements take center stage, usually referring to personal or collective memories, experiences, and dreams with clearly autobiographical content, or folk myths and traditions with strong symbolic significance. Sometimes the themes take on a surreal dimension, as they are presented in unexpected combinations. The frequent presence of the painter's own image in his paintings, as well as his obsession with certain thematic motifs (trees, sea and ships, heroes, horsemen, couples, etc.) reveal a deep sense of identification between the artist and his work. The three-dimensional wooden constructions, which he later introduced into his practice, function as an extension of his painting, reinforcing its communicative immediacy.

He has presented numerous solo exhibitions, mainly in Greece (Athens, Thessaloniki, Chania, etc.), and has participated in many group exhibitions in Greece and abroad. He took part in the 2nd and 3rd Biennials of Young Artists from Europe and the Mediterranean (Thessaloniki 1986, Barcelona 1987) and in the 16th Alexandria Biennial (1987). In 2005, an album-sketchbook with his drawings was published. In 2012, a retrospective exhibition of his work was held at the Benaki Museum, and a monographic study of his entire oeuvre was published in Greek, entitled "My Strength is Made Perfect in Weakness" (translation), written by Filippos Begleris.