Saskatchewan is a province in Western Canada. It is bordered to the west by Alberta, to the north by the Northwest Territories, to the east by Manitoba, to the northeast by Nunavut, and to the south by the United States (Montana and North Dakota). Saskatchewan and neighbouring Alberta are the only landlocked provinces in Canada. In 2025, Saskatchewan's population was estimated at 1,253,569. Nearly 10% of Saskatchewan's total area of 651,900 km² (251,700 sq mi) is fresh water, mostly rivers, reservoirs, and lakes.

Saskatchewanians live primarily in the southern prairie half of the province, while the northern half is mostly forested and sparsely populated. Roughly half live in the two largest cities, Regina (the provincial capital) and Saskatoon (the largest city). Other notable cities include Prince Albert, Moose Jaw, Yorkton, Swift Current, North Battleford, Estevan, Weyburn, Melfort, and the border city of Lloydminster. English is the primary language of the province, with 82.4% of Saskatchewanians speaking English as their first language.

Saskatchewan has been inhabited for thousands of years by indigenous peoples. Europeans first explored any part of the province in 1690 and first settled in the area in 1774. It became a province in 1905, carved out from the vast North-West Territories, which had until then included most of the Canadian Prairies. In the early 20th century, the province became known as a stronghold for Canadian social democracy, with the 1944 provincial election electing North America's first socialist government to office.

Saskatchewan's economy is based on agriculture, mining, and energy. In 1992, the federal and provincial governments signed a historic land claim agreement with First Nations in Saskatchewan, granting these nations compensation which they could use to buy land on the open market for the bands. Presently, Saskatchewan is governed by the Saskatchewan Party, led by Premier Scott Moe, which has been in power since 2007.

The name of the province is derived from the Saskatchewan River. The river is known as ᑭᓯᐢᑳᒋᐘᓂ ᓰᐱᐩ kisiskāciwani-sīpiy ("swift flowing river") in the Cree language. Anthony Henday's spelling was Keiskatchewan, with the modern rendering, Saskatchewan, being officially adopted in 1882, when a portion of the present-day province was designated a provisional district of the North-West Territories.

Saskatchewan is the only province without a natural border. As its borders follow geographic lines of longitude and latitude, the province is roughly a quadrilateral, or a shape with four sides. However, the southern border on the 49th parallel and the northern border on the 60th parallel curve to the left as one proceeds east, as do all parallels in the Northern Hemisphere. Additionally, the eastern boundary of the province follows range lines and correction lines of the Dominion Land Survey, laid out by surveyors before the Dominion Lands Act homestead program (1880–1928).

Saskatchewan is bounded on the west by Alberta, on the north by the Northwest Territories, on the north-east by Nunavut, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota. Saskatchewan has the distinction of being the only Canadian province for which no borders correspond to physical geographic features (i.e., they are all parallels and meridians). Along with Alberta, Saskatchewan is one of only two land-locked provinces.

The overwhelming majority of Saskatchewan's population is in the southern third of the province, south of the 53rd parallel.