Col Jensen started his military career in the Lower Canada College cadet corps in Montreal. While attending McGill University to obtain his BComm and MBA, he joined the Royal Montreal Regiment in 1961 as a 2Lt. In 1968 he was promoted to Major and in late 1969 his employer moved him to Winnipeg.
He joined the Queens Own Cameron Highlanders and in 1970 he was posted to Prairie Militia Area Headquarters located in Winnipeg. When his employer moved him to Toronto in 1971, he joined the Toronto Scottish Regiment as the Operations Officer. In 1973, he was posted to Central Militia Area Headquarters and in 1974 he joined the 48th Highlanders of Canada where he commanded a rifle company.
In 1982, Col Jensen was promoted Lieutenant Colonel and appointed Commanding Officer of the 48th Highlanders. After completing his tour as Commanding Officer in 1985, he was posted to Toronto Militia District Headquarters (now 32 Brigade) and in 1989 he was promoted to Colonel to command Toronto Militia District. He became Deputy Chief of Staff (Operations) of Land Force Central Area in 1992 and retired from the Forces, in 1996.
Col Jensen’s civilian career was with several financial institutions and he retired as a Vice-President of the Bank of Nova Scotia in 2001.
He has served on a few not for profit boards and was President of the Toronto Philharmonia Orchestra for several years. After retirement from Scotiabank, he did some consulting for a few years – mostly with small businesses – and started a software development company creating database applications and web sites for small businesses. In 2020 he was asked to lead a team to redevelop the Regimental web site and, when that project was completed, he took on the development of a web site for the Regimental Museum and the redevelopment of the web site for the 15th Battalion CEF Memorial Project.