Sir Hugh Allan (September 29, 1810 – December 9, 1882) was a Scottish-Canadian shipping magnate, financier and capitalist. By the time of his death, the Allan Shipping Line had become the largest privately owned shipping empire in the world. He was responsible for transporting millions of British immigrants to Canada, and the businesses that he established from Montreal filtered across every sphere of Canadian life, cementing his reputation as an empire builder. His home, Ravenscrag, was the principal residence of the Golden Square Mile in Montreal.

Born at Saltcoats in North Ayrshire, Scotland, he was the second son of Captain Alexander Allan and Jean Crawford (1782–1856). He was a first cousin of Sir Alexander Tilloch Galt, and his father was a first cousin of the Scottish bard, Robert Burns. In 1819, Allan's father established the Allan Shipping Line, which became synonymous with transporting goods and passengers between Scotland and Montreal. Allan received a parish education at Saltcoats before starting work in 1823 at the family's counting house of Allan, Kerr & Co., of Greenock. Three years later, he was sent by his father to Montreal to work as a clerk for a grain merchant, William Kerr. In 1830, he took a year off to travel through his native Scotland (he later named his home, Ravenscrag, after his favourite childhood haunt in Ayrshire) and continued via London, New York and Upper Canada.

Returning to Montreal in 1831, Allan became a commission merchant with one of the city's leading importers, who had also acted as the Montreal agent for his family's company, J & A Allan, back in Scotland. Concentrating on shipping, shipbuilding and purchasing grain, Allan advanced rapidly, aided by capital raised and contacts gained through family connections, as well as social bonds he developed himself in the predominantly Scottish business community at Montreal. By 1835, Allan was made a partner in the firm that from then was known as Millar, Edmonstone & Co. With his father's encouragement and capital, Allan expanded the company's shipping operations, and J & A Allan (then headed by his elder brother, James, in Glasgow) became closely involved with building of the merchant fleet. By the time (1839) Hugh's younger brother, Andrew, had joined now Edmonstone, Allan & Co., it had the largest shipping capacity of any Montreal-based firm.

By the 1850s, Edmonstone & Allan was described by a credit-rating service as an "old, safe and respectable House... one of the wealthiest concerns in the Province", known for its responsible management and its links to trading houses in London, Liverpool, and Glasgow. Helped by Allan's spreading influence into allied shipping, railway and banking concerns, the firm was "as good as a bank". From 1863, the company became known as H & A Allan, of Montreal — one segment, but an important and intricate part of the Allan family's empire.

In 1851, Hugh Allan had been elected President of the Montreal Board of Trade. As an entrepreneur and the chosen head of Montreal's business community, he used this position to advocate for the establishment of a regular government-subsidised steamship line between Britain, Montreal and Portland. The service, Allan declared, would deliver Royal Mail to both sides of the Atlantic Ocean while transporting immigrants to North America. Though it was Allan's idea, competition for the contract was fierce. Despite significant support on both sides of the Atlantic and careful preparation, Allan lost the bid in 1853. However, the consortium that won the contract, headed by Samuel Cunard, ran into trouble almost immediately and Allan reacted by building more ships on the Clyde, using superior technology (notably the Canadian and the Indian). These ships formed the nucleus of Allan's Montreal Ocean Steamship Company, incorporated by him and his brother, Andrew, in 1856. It was carefully created to be Canadian, but it was inextricably linked (and financed) by the Allan family in Scotland. In 1856, with the help of conservative politicians such as Sir John Rose, Sir George-Étienne Cartier and Lewis Drummond, the Montreal Ocean Steamship Company (popularly referred to as the Allan Line) wrested back the contract from Samuel Cunard. By 1859, service was weekly, and Allan reported his capital investment in the company at £3.5 million.

Beyond mail and emigrating passengers, the Allan Line carried royalty (converting one of its ships with no expense nor detail to attention spared), troops (in the Crimean and Zulu wars), general cargo, manufactured goods and much needed Canadian wheat to Britain. After the Victoria Bridge opened in 1859, Allan became dependent on the Grand Trunk Railway and signed a ten-year deal with them. But he soon became frustrated with the railway when he wanted them to triple their deliveries from the American Midwest, and he felt threatened by the railway's plans to form a steamship line of its own with rival firms in New York and Boston. By 1873, Allan expressed "a desire to protect ourselves".

At the same time that Allan was falling out with the Grand Trunk Railway, the Canadian government had committed to building a railway across to British Columbia. Though slow to move into the railway business, by the 1870s, Allan had become Canada's most flamboyant railway entrepreneur. He helped to place trusted colleagues (such as his lawyer John Abbott, agent Louis Beaubien and the politician John Hamilton) in senior positions with railways connected to the venture. Allan himself invested heavily, particularly in those that would link the Port of Montreal to the Canadian West, and he became president of the Montreal Northern Colonization Railway in 1871. Garnering the support of French-Canada (helped in a large part by his relationship with Antoine Labelle), Allan's railway gained major benefits in Quebec, including a $1 million subscription from the City of Montreal. Allan was reckoned the most influential capitalist in 1870s Canada, and having staved off American interest in the Pacific Railway, he was the logical choice for winning the contract.

He created a syndicate to build the national railway, promised as a condition of British Columbia joining Confederation. To ensure the contract, he bribed Prime Minister Sir John A. Macdonald,^{[citation needed]} subscribing over $350,000 for Macdonald's re-election campaign in 1872, but the Pacific Scandal (and Macdonald's defeat) ended his dreams of supremacy in the railway business. However, through his bank, the Merchants' Bank of Canada, he still financed and maintained a vested interest in many of the Canadian railway companies.