Alberta ( al-BUR-tə) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Territories (NWT) to the north, and the U.S. state of Montana to the south. It is one of the only two landlocked provinces in Canada (Saskatchewan being the other). The eastern part of the province is occupied by the Great Plains, while the western part borders the Rocky Mountains. The province has a predominantly continental climate but experiences quick temperature changes due to air aridity. Seasonal temperature swings are less pronounced in western Alberta due to occasional Chinook winds.

Alberta is the 4th largest province by area at 661,848 km² (255,541 sq mi), and the 4th most populous, being home to 4,262,635 people. Alberta's capital is Edmonton, while Calgary is its largest city. The two are Alberta's largest census metropolitan areas. More than half of Albertans live in either Edmonton or Calgary, which contributes to continuing the rivalry between the two cities. English is the official language of the province. In 2016, 76.0% of Albertans were anglophone, 1.8% were francophone and 22.2% were allophone.

Alberta's economy is based on hydrocarbons, petrochemical industries, livestock and agriculture. The oil and gas industry has been a pillar of Alberta's economy since 1947, when substantial oil deposits were discovered at Leduc No. 1 well. It has also become a part of the province's identity. Since Alberta is the province most rich in hydrocarbons, it provides 70% of the oil and natural gas exploited on Canadian soil. In 2018, Alberta's output was CA$338.2 billion, 15.27% of Canada's GDP.

In the past, Alberta's political landscape hosted parties like the centre-left Liberals and the agrarian United Farmers of Alberta. Today, Alberta is generally perceived as a conservative province. The right-wing Social Credit Party held office continually from 1935 to 1971 before the centre-right Progressive Conservatives held office continually from 1971 to 2015, the latter being the longest unbroken run in government at the provincial or federal level in Canadian history.

Before becoming part of Canada, Alberta was home to several First Nations like Plain Indians and Woodland Cree. It was also a territory used by fur traders of the rival companies HBC and NWC. The Dominion of Canada bought the lands that would become Alberta as part of the NWT in 1870. From the late 1800s to early 1900s, many immigrants arrived to prevent the prairies from being annexed by the US. Growing wheat and cattle ranching also became very profitable. In 1905, the Alberta Act was passed, creating the province of Alberta. Massive oil reserves were discovered in 1947. The exploitation of oil sands began in 1967.

Alberta is renowned for its natural beauty, richness in fossils and for housing important nature reserves. Alberta is home to six UNESCO designated World Heritage Sites: The Canadian Rocky Mountain Parks, Dinosaur Provincial Park, the Head-Smashed-In Buffalo Jump, Waterton-Glacier International Peace Park, Wood Buffalo National Park and Writing-on-Stone Provincial Park. Other popular sites include Banff National Park, Elk Island National Park, Jasper National Park, Waterton Lakes National Park, and Drumheller.