Edgar Dewdney, PC (November 5, 1835 – August 8, 1916) was a Canadian surveyor, road builder, Indian commissioner and politician born in Devonshire, England. He emigrated to British Columbia in 1859 in order to act as surveyor for the Dewdney Trail that runs through the province. In 1870, Dewdney decided to take up a role in Canadian government. In this year, he was elected to the Legislative Council of British Columbia as a representative from the Kootenay region. In 1872, he was elected as a Member of the Parliament of Canada for the Yale region representing the Conservative party. He was reelected to this position in 1874 and again in 1878. Dewdney served as Lieutenant Governor of the North-West Territories from 1879 to 1888, and the fifth Lieutenant-Governor of British Columbia from 1892 to 1897. Additionally, he served as the Indian commissioner in the North-West Territories from 1879 until 1888. In 1897, Dewdney retired from politics and began working as a financial agent until his death in 1916.

Throughout his political career, Dewdney played a role in the settlement of western Canada and defining the relationship between the government of Canada and the Indigenous peoples of the North-West in the nineteenth century. Dewdney experienced several political and humanitarian issues throughout his political appointments. As Lieutenant-Governor of the North-West Territories, Dewdney had to manage with a starvation crisis faced by the Indigenous peoples after years of deliberate extermination of buffalo herds, promoted by the Government of Canada to force the Indigenous inhabitants off the land prior to its settlement. Additionally, as Indian Commissioner, Dewdney subsequently tackled issues pertaining to the North-West Rebellion of 1885, and selected Regina to be the capital of the North-West Territories.

Edgar Dewdney was born in Bideford, England to parents Charles Dewdney and Fanny Hollingshead. He grew up in a wealthy family, providing him with many social opportunities. Dewdney had two marriages, neither producing any children. The first marriage was to Jane Shaw Moir in 1864, and the second in 1909 to Blanche Elizabeth Plantagenet Kemeys-Tynte. Dewdney originally wanted to pursue a career in civil engineering, studying the subject at Cardiff University. After his civil engineering training in 1859, he decided to start a life in the Pacific northwest in hopes of making a fortune with his newly acquired qualifications. Dewdney was also motivated to move to the North-West Territories after the discovery and further mining of gold in the Fraser Valley. He was active in the development of pack trails in the colony of British Columbia including the Dewdney Trail which became the main trail into the interior of the colony.

Dewdney was active in political life in British Columbia throughout the 1860s. Dewdney had a limited understanding of the functions of Canadian politics when his interests first piqued. After a few years in Provincial politics, Prime Minister John A. Macdonald requested Dewdney to become the Indian Commissioner in the North-West, as he knew of the “Indians” in the area quite well. Dewdney had an advantage due to his general knowledge of Indigenous peoples and that he did not originate from Ottawa. Later in his life, Dewdney held dual titles of Indian Commissioner and Lieutenant-Governor of the North-West Territories. He was also the Lieutenant-Governor of British Columbia and after three years retired and became a surveyor. Due to his prestigious career in politics, Dewdney was considered suitable to conduct the study and surveying of the Cascades. He discovered three routes, Allison, Coquihalla, and Railroad Passes in his 1902 exhibition. However, he disclosed that he never liked any of these routes due to their engineering difficulties. As a result, Dewdney suggested the Canadian Pacific Railway (CPR) should be built from Midway to Princeton, then north to Merritt and Spences Bridge, and have Fraser Canyon as the way through the Cascades. Dewdney is recognized as a legendary trail builder of colonial days in British Columbia, as this played a large role in the westward expansion of Canada. Despite this recognition, he faced issues regarding Canadian expansionism and the effect on Indigenous peoples.

Dewdney was originally employed as a surveyor, and supervised the survey of New Westminster. In 1865, Dewdney was appointed by Governor Frederick Seymour to oversee the construction of a trail to the East Kootenay region of the British Columbia Interior so that coastal merchants might benefit from the burgeoning trade associated with gold mining in that area. This was also done to secure a line of communication within the region to prevent an American takeover of that part of the province. Although used for only a few years, parts of the Dewdney Trail, as it was known, remain to this day and are used for recreational hiking. Provincial Highway 3 largely follows the route of the Dewdney Trail.

From 1868 to 1869, Dewdney became active in Colonial politics, representing the electoral district of Kootenay in the Legislative Council of British Columbia. After the colony joined Canadian Confederation in 1871, he served as a Conservative Member of Parliament for the riding of Yale following his election in 1872. He was appointed a member of Prime Minister Sir John A. Macdonald's cabinet in 1879, where he served as Indian commissioner for the North-West Territories until 1888.

In 1881, Macdonald arranged Dewdney's appointment as Lieutenant Governor of the North-West Territories, then an executive position. Dewdney resigned his seat in the Commons, but remained Indian Commissioner during his term as Lieutenant-Governor, which lasted until 1888. Macdonald, along with being Prime Minister, held the cabinet post Minister of the Interior. Dewdney took orders directly from Macdonald. Responsible government had not been granted to the North-West Territories, so Dewdney was the Territories' head of government. Perhaps his most notable decision in office was changing the territorial capital from Battleford to Wascana – Cree for "Pile of Bones" – in 1883: a featureless location without water apart from a short spring run-off Wascana Creek, trees or topography. This is where Dewdney had secured a substantial real estate for himself adjacent to the near-future planned Canadian Pacific Railway line. Other townsites were also considered probable territorial capitals, including Fort Qu'Appelle and Qu'Appelle, the latter to the extent of having been designated the cathedral city of the new Diocese of Qu'Appelle by the Church of England in Canada. The matter was a national scandal at the time. Still, the initial major street of Pile of Bones, later renamed Regina by Princess Louise, Marchioness of Lorne, was called Dewdney Avenue.

After his term as Lieutenant Governor of the North-West Territories, Dewdney was again elected to Parliament and served as the member for Assiniboia East (now southeastern Saskatchewan) from 1888 to 1891. During this period he also served as Minister of the Interior and Superintendent of Indian Affairs.