Vlassis Caniaris was born in Athens in 1928. At first he studied Medicine, which he gave up devoting himself to painting. After attending preliminary painting lessons at Panos Sarafianos' studio, he studied at the Athens School of Fine Arts (1950-1955), under U. Argyros, Y. Pappas, and Y. Moralis. He also worked on stage design as an assistant to Yannis Tsarouchis. After his graduation, he settled in Rome, Italy. His first solo exhibition in Athens (Zygos gallery, 1958) was one of the earliest presentations of abstract art n Greece.

The period following his early phase, he created artworks with layers of plastered papers (Tribute to the walls of Athens) and, since 1960, he starts to abandon conventional canvas painting. He settles in Paris, and comes into contact with the group of Nouveaux Realistes and Pierre Restany. He has already begun using metal mesh and plastered materials in three-dimensional constructions, now adding real objects in the form of assemblage. In 1964, he participated in Restany's much-debated exhibition Three Proposals for a new Greek sculpture (along with Danil and Kessanlis), a parallel event of the 32nd Venice Biennale. After the 1967 military coup he returned to Greece and in 1969, he presented an exhibition of plaster and barbed wire constructions (New Gallery, Athens), which evolved into a top artistic event, functioning both as an anti-dictatorship demonstration, and as an innovative artistic approach. Immediately after, he was forced to return to Paris.

From 1973 to 1975 he worked in West Berlin on a DAAD scholarship. There, he was able to complete the Gastarbeiter-Fremdarbeiter series, including installations of barbed wire dummies with old clothes and everyday objects of immigrants, which were exhibited in many German museums. This kind of anthropomorphic constructions would dominate his following artworks, through which he harshly criticized on problematic aspects of the socio-political reality (Helas Hellas, 1980, North-South, 1988, etc.).

In 1975 he was elected Professor to the Seat of Painting, at the National Technical University of Athens, School of Architecture, and shortly after he settled permanently in Greece (1976). Before his death (Athens, 2011) he had exhibited his work in more than twenty solo shows in Greece and abroad. He participated, among others, in the Biennales of San Marino (1963), Sao Paulo (1965) and Venice (1988), the 6th Documenta of Kassel (1977) and Belgium's Europalia (1982). His most significant retrospectives were presented in 1991-1992 (Thessaloniki, the Hague and Berlin), in 1999 (Athens National Art Gallery), in 2000 (State Museum of Contemporary Art, Thessaloniki) and in 2008 (Benaki Museum). A monograph on his oeuvre was published in 2009.