(August 24, 1883 – October 4, 1965) was an Icelandic-Canadian chemist.
He was the head of the Department of Chemistry at the University of Saskatchewan.
Thorvaldson and his team at the National Research Council developed a sulphate-resistant cement in 1919 which prevented decay and deterioration in existing structures.
He served as president of the Canadian Institute of Chemistry in 1941.
In 1946 he was named first dean of graduate studies at the University of Saskatchewan.