[1] He spent part of childhood in Penang due to his father's work and attended St. Xavier's Institution.

He continued his education at St. Joseph's Institution and Raffles Institution before enrolling into Raffles College (a forerunner of the National University of Singapore) in 1933 and graduating in 1936 with a Diploma in Arts with Class One honours.

[2] Byrne was appointed as the magistrate of the Fourth Police Court to replace R. E. Turnbull in 1939.

[2] Byrne was Permanent Secretary for the Ministry of Commerce and Industry in 1957[6] and left the government post in 1958 to join politics.

[15] In 1973, he was concurrently Singapore's High Commissioner to Bangladesh, Iran, Nepal and Sri Lanka.