He was born in Canada to Alexander Dalgety, army officer, and his wife Elizabeth, née Doidge.
[2] In December 1842 he moved to Melbourne, which had only recently been established, and became manager of a new wool trading firm.
[1] In 1884, with advancing age, the increasing demand for capital and competition from joint-stock companies and banks, Dalgety incorporated his private partnerships as a joint-stock company, called Dalgety & Co, which was listed on the London Stock Exchange.
By that time it had operations in London, Melbourne, Geelong, Launceston, Dunedin, Christchurch and Sydney.
[1] In December 1855 he married Blanche Trosse Allen and together they had five sons and five daughters, none of whom went into the business.