Cargill was born in Glasgow, the second son of David Sime Cargill, founder of the Burmah Oil Company, and his first wife Margaret (née Traill), who died when he was five.

In 1904, he succeeded his father as chairman of the Burmah Oil Company and its associates, remaining in the post until 1943.

Cargill (through his subsidiary Concessions Syndicate Ltd) provided from Glasgow the necessary finance, plant and equipment, and skilled manpower for the long drawn-out task of wresting oil from the inhospitable land of Persia.

He later served as figurehead of these companies, leaving the active running of them to their managing directors.

[2][3] Cargill was created a baronet, of Glasgow, in the 1920 New Year Honours.