William Armour was born in Dunedin on 30 April 1880, to Scottish immigrants Elizabeth Allan and her husband, Hugh Armour.

He attended Otago Boys' High School, Dunedin Training College and the University of Otago, graduating in 1902 with an MA with honours.

Armour taught at schools in Dunedin, Wanganui and Invercargill, before being made director of Wanganui Technical College in 1911.

That year he also received an MSc and in 1912 married Margaret Stevenson with whom he would have six children.

Armour retired at the end of 1942 and returned to Napier where he died on 21 April 1967.