Air Chief Marshal Denis Anthony La Fontaine was born on 17 September 1929.His ancestors were in military service. His father, Je La Fontaine was Major General Of Indian Army. His Grandfather was also an officer of Indian Army. Denis Anthony received his education from St. Anthony`s High School at Lahore. He graduated from St. George`s College at Musoorie. After completing his formal education he joined in Indian Air Force in 1947. Denis Anthony La Fontaine took training on Tigermoth aircraft, Spitfires and Tempests aircraft. In 1950 he was commissioned into the flying branch of Ambala. In 1951 Denis Anthony was posted to No.7 Battle Axes Squadron flying the Tempests. He was among the first pilots who got training in flying the jets. After that he did All Purpose Instructors Course. Next three years he flew instructional flights. In 1956 Denis Anthony La Fontaine was appointed to the No.2 Squadron flying the Toofanis. After that, as a Senior Flight Commander he was posted to No.29 Scorpions. He got a promotion and was appointed to No.47 Black Archers as Squadron Leader. Under his leadership this Squadron won the Mukherjee Trophy. Denis Anthony La Fontaine was promoted to the rank of Wing Commander he was posted to No.14 Fighting Bulls Squadron at Kalaikunda. During the Indo-Pak war in 1965 he flew Subsonic Hawker Hunter but his unit did not succeeded in this war.

Later Air Marshal Denis Anthony La Fontaine was appointed, as the chief instructor of Air Force Academy. He was responsible for the up gradation of the quality of the flying training. When war broke out in 1971 he was appointed as Senior Staff Officer to the Maritime Air Operations sector in Bombay. After the war Air Marshal Denis Anthony commanded Western Air Command and later became Senior Air Staff Officer of WAC. Denis Anthony La Fontaine was promoted to the rank of Air Marshal and was posted as the Air Officer Commanding-in-Charge (Personnel) in the Air Headquarters. He also commanded Central Air Command and Western Air Command as AOC-in-C. He was appointed as chief of Air Staff after the sudden death of Air Chief Marshal L.M. Katre. During long tenure Air Marshal Denis Anthony La Fontaine was awarded the Vayu Sena Medal, Ati Visist Sena Medal, and Param Visist Sena Medal for dedicated service to the nation.