Charles August Thelander, son of Swedish migrants Elias and Karna Thelander, was born in Yangan, Queensland, Australia, in 1883. He attended local schools in Yangan and Toowoomba and began studies at the University of Edinburgh in 1902. In addition to funding from the Queensland Government for these studies, he won the Edinburgh University Vans Dunlop scholarship. Thelander graduated on 26 July 1907 with the degrees fo M.B. Ch.B., and he registered as a medical practitioner in Edinburgh on 29 July 1907.

He became a House Physician, then House Surgeon, at the Royal Infirmary of Edinburgh shortly after, and there he met Hélène Ramuz from Switzerland who would later become his wife. In 1909 he visited Europe, including Germany, and he made a short trip to Australia returning to Edinburgh in 1910. He returned to Australia permanently in 1911 to take up a medical career in Brisbane. Also in 1911, he married Hélène Ramuz. In 1922 however, she died leaving Charles a widower with three sons (Charlie, Paul, and Digger). In 1924 he remarried. His second wife was Daphne Morgan, niece of the former Queensland Premier Sir Arthur Morgan. They had a daughter (Betty).

In Brisbane, Australia, Thelander headed a group of medical practitioners - Ballow Chambers Ltd - which acquired a site on Wickham Terrace, Spring Hill, in the city, in 1924. The three-storeyed masonry office building is now heritage-listed.

In later years, Parkinson's Disease gripped his life, and Charles A. Thelander died in 1959.