Colin Thiele was a bilingual child in a German farming community and from a young age read widely in both German and English. His parents were Carl Wilhelm and Amalie Anna (nee Wittwer) Thiele. He attended Julia and Eudunda primary schools and Kapunda high school. Henry Lawson (q.v.) was an early influence on his writing as Thiele could relate to the rural characters and settings of While the Billy Boils. He enrolled at the University of Adelaide in 1937, forming lasting friendships with the poets Rex Ingamells, Max Harris, Flexmore Hudsonwi), Geoffrey Dutton, Paul Pfeiffer and D.B. Kerr (qq.v.), and seeing some of his early poems published in Jindyworobak Anthologies, Angry Penguins and Poetry. Thiele graduated from the University of Adelaide in 1941 and then served as a radar mechanic in northern Australia with the RAAF during the Second World War. His teaching career began in Port Lincoln in 1946 and led to his appointment as principal of Wattle Park Teachers' College, Adelaide, in 1965. At university Thiele had been impressed by the teaching excellence and dedication of Douglas Mawson, an inspiration for his own highly regarded reputation as an educator.
Thiele combined his professional life as a teacher and speaker with his prolific writing of poetry, fiction, children's books, biography, radio plays and educational texts. Most of his books are set in South Australia, although his concerns are universal. Among his best known children's books are Storm Boy (1963) and Blue Fin (1969) - both of which were made into films.
Thiele's childhood is evident in many books, including The Sun on the Stubble (1961), later made into an award-winning television series. Thiele wrote and edited over 100 books, saying that he had 'a particular affection' for Storm Boy, Pinquo, Jodie's Journey, Blue Fin, Coorong and Heysen of Hahndorf, because in their writing he came closest to 'getting it right'.
Known as an environmentalist, Thiele wrote several books about endangered Australian locations, including Coorong (1972) and Range Without Man : The North Flinders (1974). Many of his books have been translated and published abroad. In 1977 he was made a Companion of the Order of Australia for his services to literature and education. Thiele was known as a faithful correspondent: he received and answered thousands of letters from children, kept at the National Library and the University of South Australia. Diagnosed with rheumatoid arthritis in the 1950s, Thiele had many joint replacement operations and settled in Queensland with his wife Rhonda in 1993. He continued writing until close to the time of his death.
Thiele was chosen as one of 150 great South Australians by a panel of The Advertiser senior writers to celebrate the 150th anniversary of The Advertiser newspaper, 12 April 2008.