Haanes was born in Drammen as the son of businessman Thorgny Haanes and his wife Hedvig Kristine Clausen. He grew up in Aker, along with five brothers. He worked some years in a sports shop, and eventually started his own little sports shop in Oslo in 1936. In 1938 he married Claire Höckert. Several of his brothers were also sportsmen. His brothers Hans Jacob and Thorgny were tennis players, both National Champions in double (with Johan). His brother Sigurd was an excellent ski jumper who placed fourth at the FIS Nordic World Ski Championships 1937. His brother, Reidar Haanes, became an acclaimed sports journalist, who also wrote the book ‘Store dager i norsk idrett’ (1952) and ‘Njårds historie’