Wuorenheimo's parents were Senator Johan Erik Bergbom and FredrikaJuliana Rochier. His siblings were Kaarlo and Emilia Bergbom, known as the founders of the National Theatre, and Augusta af Hörlin, an activist. Wuorenheimo's first wife from 1877 was Augusta Fredrika Theresa Rotkirch and his second from 1884 was Agnes Augusta Charlotte Idman. They had three children. His son from his second marriage was Aarne Vuorenheimo, a missionary counselor and executive director of Suomi-Film. The writer Toivo Tarvas was the adopted son of Osian Wuorenheimo. Wuorenheimo's father-in-law, Gustav Fredrik Rotkirch, and his two sons-in-law, SamuelWerner von Troil and Gustav Samuel von Troil, were senators.