Spyros Vassiliou (Greek: Σπύρος Βασιλείου; June 16, 1903 – March 22, 1985) was a Greek painter, printmaker, illustrator, and stage designer. He became widely recognized for his work starting in the 1930s, when he received the Benaki Prize from the Athens Academy. The recipient of a Guggenheim Prize for Greece (in 1960), Spyros Vassiliou's works have been exhibited in galleries throughout Europe, in the United States, and Canada. For many years Vassiliou taught theatre. As early as 1927 he designed sets and costumes for the stage. He also worked in film. Well known projects include Michalis Kakoyiannis' 1962 adaptation of Euripides, and Elektra, starring Irene Papas and close friend Manos Katrakis.

During the years of the German occupation of Greece (1941-1945), when painting supplies were scarce, Vassiliou turned to engraving and woodcuts. Works such as The Burial of Palamas and The Mourning of the Kalavrytans (1943) became famous in Greece as symbols of freedom. His activity during those years also included the illustration and underground publication of three manuscript volumes as well as woodcut prints for magazines.

Over the years, dozens of Vassiliou's illustrations and paintings were printed on covers of books and magazines including The Athenian (magazine) and children's magazine To Rodi, where he also critiqued children's drawings.

The Greek National Tourism Organization used ones of Vassiliou illustrations, the "Island of Poros", as a promotional poster for Greece in 1948.