Harry Marks had a Jewish background, reflected in some of his wrtiting. He was one of the first Australian novelists to write about the experience of migrants. Marks served in the defence forces during World War II and lived for a year in England.

Marks started writing in his teenage years, acknowledging the ongoing encouragement given to him by Alan Marshall (q.v.). Marks served as a president of the Victorian Fellowship of Australian Writers and was chairman of the adjudicators for the Australian Industry Awards for Young Writers. He also served as editor of Concern and Australian New Writing.