Panagiotis Tetsis (1925-2016) was born in Hydra and moved with his family to Piraeus in 1937. However, he returned to Hydra every summer, where he met N. Hatzikyriakos-Gkikas and D. Pikionis, whom he considered his teachers. In 1940, he took his first painting lessons from the German Klaus Frieslander and then studied at the Athens School of Fine Arts (1943–1949). A year before graduating, he held his first solo exhibition (1948, Romvos). In 1951, he began teaching as a curator in the freehand drawing department at the National Technical University of Athens, under Professor Hatzikyriakos-Gkikas. After receiving a scholarship from the State Scholarship Foundation, he continued his studies in Paris (1953-56), where, among other things, he took courses in copperplate engraving with Ed. Goerg at the Ecole des Beaux Arts.

From the beginning, his painting incorporated elements of modernism and abstraction, while remaining representational. Since then, his thematic choices, from large-scale compositions featuring multiple figures to landscapes, serve as catalysts to highlight purely painterly values. Throughout his long career, he has developed the compositional, chromatic, and expressive potential of oil painting, as well as pastel, watercolor, and ink. Throughout his work, light determines the structure of the composition as an integral component of colour.

He taught at the Design Department of the Athenian Technological Group (1959-1962) and was co-founder and teacher at the Free School of Fine Arts (Vakalo Art & Design College). He was elected professor at the Athens School of Fine Arts (1976), where he taught until 1991 and served as rector from 1989. In 1993, he became a member of the Academy of Athens, and in 1999, he was honored with the Grand Cross of the Order of the Phoenix.

He has held more than 90 solo exhibitions and taken part in numerous group exhibitions in Greece and abroad. He participated in the São Paulo Biennial (1957) and the Alexandria Biennial (1959). His retrospective exhibition entitled 35 Years of Painting (1992, Pieridis Gallery) toured the municipal galleries of Mytilene, Patras, Kalamata, Rhodes, and Chania. Other retrospective exhibitions followed at the National Gallery (1999), Florence, Cyprus, and elsewhere. He has published four books with his texts and numerous articles in the press.