Sioux Lookout is a town in Northwestern Ontario, Canada, with a population of 5,838 people (up 10.8% since 2016). Known locally as the "Hub of the North", it is serviced by the Sioux Lookout Airport, Highway 72, and the Sioux Lookout railway station. According to a 2011 study commissioned by the municipality, health care and social services ranked as the largest sources of employment, followed by the retail trade, public administration, transportation and warehousing, manufacturing, accommodation and food services, and education.

Although downtown Sioux Lookout is located 71 kilometres (44 mi) from the Trans-Canada Highway, the municipality covers the ends or beginnings of provincial highways 664, 642, 516, and 72. Sioux Lookout is also a key airport hub for numerous northern and Indigenous communities in Northwestern Ontario and remains a service stop for The Canadian, a transcontinental passenger train operated by Via Rail, and a busy railway junction for the northwestern Ontario segment of Canadian National Railway's transcontinental Class 1 railroad.

Fishing camps in the area allow access to an extensive lake system fed by the English River. The town is surrounded by several beaches, including Umphreville Park, a historical site that predates the town itself. During the summer months, Sioux Lookout's population rises as tourists, mostly American, arrive to take advantage of the multitude of lakes and rivers in the area. Experienced guides, employed by the camps, can locate the best locations and also provide an educated tour of the unique land known affectionately as "sunset country".

Sioux Lookout's name comes from a First Nations story and a local mountain, Sioux Mountain, which served as a lookout point for the Ojibwe people. Being able to scan the surrounding area for some distance enabled the Ojibwe men to potentially detect any approaching Sioux warriors, with sufficient time to guide the women and children to safety before intercepting the enemies. From Sioux Mountain, a careful eye could catch the sun reflecting off of birch bark canoes crossing the nearby rapids. Illustrating this old story on the front page of the local newspaper, "The Sioux Lookout Bulletin", is an iconic image of an Indigenous man holding a hand above his eyes as he scans the water and the surrounding terrain.

Sioux Lookout was incorporated in 1912 and was a terminal and junction on the National Transcontinental Railway. For many years, Sioux Lookout was simply a railway town. At one point, gold was discovered in Red Lake; the town subsequently became one of the leading Canadian aviation centres during the 1920s and 1930s. From circa 1933 to 1937, the Hudson's Bay Company operated a fur-trade post at the town along the English River near the north shore of Minnitaki Lake.

During the Cold War, from 1952 to 1967, CFS Sioux Lookout, 6.0 km (3.7 mi) west, was a radar base forming part of the Pinetree Line to monitor any activity from the Soviet Union.

Today, the Canadian National Railway (CNR) is a significant employer, although it is no longer the largest employer in the area, nor is the forest products industry; Sioux Lookout has become a hub of various services catering to northern First Nations communities, such as healthcare, human and social services and education, among others. Additionally, both the provincial and federal governments are major employers within Sioux Lookout. As a result, the town barely felt the effects of the recession in the early 1980s. However, more significant demographic and employment changes took place around the time of the Great Recession and 2008 financial crisis; notably, the permanent closure of the sawmill in Hudson, along with the construction of a newer, larger healthcare complex (the Meno Ya Win Health Centre), saw several shifts in the local workforce. New and different positions were subsequently made available through the Health Centre, which also brought new workers to the area.

Urban Sioux Lookout looks out on Pelican Lake, and the municipality has initiated a lakefront improvement program to beautify this area. There are now more parks, paths, and other recreational options and amenities along the lake and surrounding lands. Numerous other lakes, rivers and water-focused activities are easily accessible, by car or boat, from Sioux Lookout. Tourism makes a significant contribution to the local economy; however, there is considerable capacity for further development, and the area's potential is only beginning to be fully recognized.