Jim Thalassoudis (b. 1962, Adelaide, Australia), is an Adelaide-based artist most recognised for his oil depictions of the dramatic and transient Australian twilight sky. 

Thalassoudis was trained at the South Australian School of Art. He studied painting (1980 to 1984) and printmaking (1985), and was awarded Bachelor of Arts in Visual Art in 1988.

Since 1983, Thalassoudis has exhibited in more than 40 solo and 100 group exhibitions. He has shown primarily in commercial galleries and art fairs in Australia, and on occasion in Hong Kong, Singapore and the United States of America. His works are in the collections of the Art Gallery of South Australia, the Gold Coast City Art Gallery, the Samstag Museum at the University of South Australia, the Art Gallery of Ballarat, Riddoch Art Gallery and Mildura Arts Centre. Thalassoudis’s paintings are also in the collections of Singtel and the Australian government.