He was born in Sydney, Australia. As a teen from 1972 until 1974, he took lessons in sketching and technical drawing including linocuts, metal. In addition, he attended woodwork workshops at Tempe high school. In1974, his family returns to Greece and continues his artistic interests at ACS-Athens Academy 1974- 1978. His studies emphasized on the mechanical and architectural design, drawing, photography, 8mm film and video. Later his artistic exploration focuses on the areas of painting, etching, sculpture, screen-printing and studies Greek Icons at the Benaki museum.
At the first phase of his career during the mid 80's, Milionis' art work is described of soft and hard edge, minimal and abstract geometric compositions with main theme the schematic human figure. In the 90's he continues to explore the human profile and has an interest for natures mortes.
In the 21st century, Milionis enriches his themes with a surreal lyrical and dreamy atmosphere of a new post-metaphysical world following Greek surrealistic models after de Chirico, Eggonopoulos, Karavousis, Yeros and Stefanou.
Milionis has presented his work in various solo and group exhibitions. In addition his work is found in several private and public institutions and private collections. In 2006 the Hellenic Post Office issues a stamp in cooperation with Patra's 2006-European Capital of Culture.