Sven Josef Cyvin (25 February 1931 – 19 September 2013) was a Norwegian chemist.
He finished his secondary education at Trondheim Cathedral School in 1949 and graduated in chemical engineering at the Norwegian Institute of Technology in 1956.
From 1964 he was a docent, and from 1970 to his retirement he was a professor of theoretical chemistry at the Norwegian Institute of Technology.
[1] Cyvin was a prolific researcher, publishing over 700 articles during his career.
was also active in the social movements Pugwash, Nei til Atomvåpen and Framtiden i våre hender.