Ottawa serves as the capital city of Canada, situated in the southeastern portion of the province of Ontario. It lies at the confluence of the Ottawa River and the Rideau River, bordering Gatineau, Quebec. The city forms the core of the Ottawa–Gatineau census metropolitan area and the National Capital Region. As the political centre of the country, it houses the headquarters of the federal government, including Parliament Hill, the Supreme Court, and the Office of the Prime Minister.

Founded in 1826 as Bytown, the settlement was named after British military engineer Colonel John By, who oversaw the Rideau Canal construction. Incorporated as a town in 1850, it was renamed Ottawa in 1855 and obtained city status. The municipality was amalgamated in 2001, swallowing the former Carleton County. The Rideau Canal is now a UNESCO World Heritage site, reflecting the area's historical significance in military logistics and timber trade during the 19th century.

The city features distinct neighbourhoods such as Upper Town and Lower Town, originally divided by language and religion. Key landmarks include Parliament Hill, the National Arts Centre, and the National Gallery of Canada. The Byward Market remains a central hub for nightlife and commerce. Unlike other federal capitals, Ottawa is not part of a special federal district but operates under regular municipal governance established by the City of Ottawa Act.

Ottawa attracts visitors with its national museums, monuments, and historic sites, drawing over 11 million tourists annually. It boasts the highest proportion of university-educated residents among Canadian cities, hosting institutions like the University of Ottawa and Carleton University. The city is known for its bilingualism, with service available in English and French, and offers a high standard of living alongside vibrant cultural and educational opportunities.

As of 2021, Ottawa had a city population of 1,017,449, making it the fourth-largest city in Canada. Its economy historically relied on timber but now centers on government, education, and technology. The city is well-connected via rail and road networks, including the transcontinental rail link established in 1886. It is one of the most visited cities in Canada, offering diverse attractions from historic sites to modern cultural institutions.