John Duncan McArthur (June 25, 1854 – January 10, 1927) was a Canadian industrialist, businessman, and railway builder. Born in Lancaster township, Glengarry County, Canada West, he worked as a farmer before heading west to Manitoba in search of work on railway crews in 1879. He quickly established himself as a capable railroad contractor and obtained numerous small contracts on the building of the Canadian Pacific Railway in Manitoba and the North-West Territories. He also built lines in Saskatchewan and Alberta, including extensive portions of the Alberta and Great Waterways Railway and Grand Trunk Pacific Railway.[1] He also had significant investments in lumber, mining, and real estate, and built the first high-rise in Winnipeg, the McArthur Building.[2] He is considered to be "one of western Canada’s greatest railway contractors" and businessmen, having built over 2,833 mi of track.[3]