The GTHA consists of the Greater Toronto Area (GTA) and the City of Hamilton.

Unlike the Golden Horseshoe, which covers a larger area, the GTHA specifically refers to the urban conurbation of these regions.

[2] The GTA is Canada's most populous metropolitan area that includes the core City of Toronto and the regional municipalities of Halton, Peel, York, and Durham (which contains Oshawa).

[7] The main series of roadways that connects all the areas together (going from Durham to Hamilton) includes highways 401, 427, 403, and the Queen Elizabeth Way.

The GTHA has regional public transport served by GO Transit and local service by multiple agencies, which mostly use the Presto card as fare payment.