The National Capital Region is an official federal designation for the Canadian capital of Ottawa, Ontario, the neighbouring city of Gatineau, Quebec and the surrounding area. Also known as Ottawa-Gatineau (or previously Ottawa-Hull), the National Capital Region has a total population of 1,130,761 (2006), and consists of an area of 5,318.36 square kilometres that straddles the boundary between the provinces of Ontario and Quebec. It is the only metropolitan area in Canada that crosses a provincial boundary.

The National Capital Region is not a separate political jurisdiction, although the National Capital Commission is heavily involved in political, cultural and land use planning matters in both cities. Proposals have sometimes been made to separate the National Capital Region from its two respective provinces, and transform it into a separate administrative area, like the District of Columbia or the Australian Capital Territory. Such proposals have never come close to implementation, and there does not currently appear to be any political will to pursue this option.

In 2006, the National Capital Commission completed work on the long-discussed Confederation Boulevard, a ceremonial route linking key attractions in National Capital Region, on both sides of the Ottawa River, in Ottawa as well as Gatineau, Quebec.

The area of the National Capital Region is very similar to that of the Ottawa-Gatineau Census Metropolitan Area, although the National Capital Region contains a number of small neighbouring communities that are not contained within the CMA.