Captain William Watson Ogilvie (15 February 1835 – 12 January 1900), commanded a division of the Royal Montreal Cavalry during the Fenian Raids.

William's grandfather, Archibald Ogilvie (1750–1820), had been a prosperous farmer at Arnieve, near Gargunnock on the River Forth, but seeing little future for his children in Scotland sold his farms and with £2,000 took his family to Quebec.

The Ogilvies shipped their first load of wheat from Manitoba in 1877 and for the next decade dominated the grain trade of western Canada, which was experiencing an agricultural boom.

They made an agreement with William Cornelius Van Horne and formed a monopoly with the Canadian Pacific Railway in exporting grain from Manitoba.

A worker at their Montreal mill recalled William Ogilvie: "He was a fine figure of a man, tall, with a keen face and impressive sideburns, the very cut of a cavalry officer.

He campaigned for his brother Alexander Walker's appointment to the Senate in 1881, noting in a letter to Prime Minister Sir John A. Macdonald the past loyalty of the Ogilvie family to the party.

By 1872, Ogilvie had purchased Rosemount House in Montreal's Golden Square Mile, the former residence of Sir John Rose, 1st Baronet.