Giannis Efthimiou studied marble sculpture in Tinos, an experience that strongly influenced his painting practice. He later graduated with distinction from the Athens School of Fine Arts (2018), having received honorary distinctions in both sculpture and painting during his studies.

His work has been exhibited in Greece and internationally and is held in private collections. He is the recipient of the Henrion Award (2025) and the G. Spyropoulos Award (2017).