Niagara is a neighbourhood located along and south of Queen Street West; it is usually bordered by Atlantic Avenue to the west, Bathurst Street to the east, and the railway corridor to the south, and so named because Niagara Street runs through the centre of it. The eastern portion of this area (with what is now called the Fashion District) was first planned as the New Town Extension when Toronto was incorporated as a city. The area was formerly working class, with many employed in industries located along the CN and CP railway corridors.

Street names in the Niagara neighbourhood are reminders of its military past. For example: Stanley Street is named after the former Stanley Barracks now located on the Exhibition grounds, Niagara Street is named after the former military capital of Upper Canada, and Tecumseh Street is named for the great warrior chief of the Shawnee, who fought for Canada, in the war of 1812.

In recent years, it has seen an explosion of new condominium loft and row house development. The area is located close to the Fashion and Entertainment districts.
The area is also part of the Trinity—Spadina riding which covers a much larger section just west of the downtown core.