During World War II, he served with the Royal Canadian Naval Volunteer Reserve and called to the Quebec bar in 1946.
Following his retirement from his law firm, he served on several board including as chair of the educational publishers McGraw-Hill Ryerson.
He was also president of CIIT Inc, vice-president of the Bank of Nova Scotia and also of the Canadian Life Assurance Company as well as on several other boards of directors.
His son, E. Jacques Courtois Jr, is a convicted insider trader having peddled confidential takeover information while a vice-president in Morgan Stanley's mergers and acquisitions department from 1974 to 1977.
Courtois Jr fled to Bogota, Colombia, where he was a fugitive for several years before pleading guilty to insider trading charges in New York in 1983.