Carl Feilberg was of Danish/English descent, and was educated in England and France. He worked for a time in a firm of London insurance brokers, but emigrated to Queensland for health reasons in ca.1867, when he was 22 years of age. Upon arrival at Rockhampton, he initially found work as a clerk and storekeeper in western Queensland, but subsequently took up farming in the Wide Bay area. He then turned to journalism, and worked on newspapers at Maryborough, and Cooktown, before moving to Brisbane, where he contributed to various metropolitan and provincial newspapers, and was employed for a time as a parliamentary reporter on the Brisbane Courier. In 1882 he moved to Melbourne, where he worked as a sub-editor on the Argus. In 1883 he returned to the Brisbane Courier, and after a short period was appointed editor, a position which he held until his death. A number of his short stories, were published in the Queenslander, the Boomerang (posthumously), and in other newspapers.
He was married to Clara Smith, daughter of a Scotsman, Walter Smith, who had settled in Maryborough from Adelaide (where Clara was born) in the 1860s and become involved in early gold and copper mining in the area, particularly the Black Snake and Mount Clara mines in the Kilkivan distract They had two sons, Walter C. and Reginald C. Feilberg, and three daughters who, at the time of her death, were mentioned as Mrs W.A. Fisher, Miss A.I. Feilberg, and Miss W.H. Feilberg ('Personal', Brisbane Courier, 11 September 1903, p.5; 'Mrs Clara Feilberg', Brisbane Courier, 20 June 1932, p.13).