Alf Collett (8 August 1844-1919[1]) was a Norwegian writer.
He published many historical and genealogical works,[2] the most important being En gammel Christiania-slægt. Optegnelser om familien Collett og Christianias fortid (1883) and Gamle Christiania-Billeder (1893).
Alf Collett was the second son of Peter Jonas and Camilla Collett. His maternal uncles included Oscar and Henrik Wergeland, and his paternal uncles included Peter Severin Steenstrup. He had one older brother Robert, a notable zoologist, and two younger brothers. He married Mathilda Sophie Kallevig (1845-1915), but they did not have any children.[1]