The city of Toronto, in Ontario, Canada, is called "the city of neighbourhoods" because of the strength and vitality of its many communities. The city has upwards of 240 distinct neighbourhoods within its boundaries. Before 1998, Toronto was a much smaller municipality and formed part of Metropolitan Toronto. When the city amalgamated that year, Toronto grew to encompass the former municipalities of York, East York, North York, Etobicoke, and Scarborough. Each of these former municipalities still maintains, to a certain degree, its own distinct identity, and the names of these municipalities are still used by their residents. The area known as Toronto before the amalgamation is sometimes called the "old" City of Toronto, "Toronto proper", the Central District or simply "Downtown".

The "former" City of Toronto is, by far, the most populous and dense part of the city. It is also the business and administrative centre of the city.

The "inner ring" suburbs of York and East York are older, predominantly middle-income areas, and ethnically diverse. Much of the housing stock in these areas consists of old pre-war single-family houses, such as the uniquely Torontonian bay-and-gable housing style, and post-war high-rises. Many of the neighbourhoods in these areas were built up as streetcar suburbs and contain many dense and mixed-use streets. Mostly they share many characteristics with sections of the "old" city, outside of the downtown core.

The "outer ring" suburbs of Etobicoke, Scarborough, and North York are much more suburban in nature (although these boroughs are developing urban centres of their own, such as North York Centre around Mel Lastman Square). The following is a list of the more notable neighbourhoods, divided by the neighbourhoods' location based on the former municipalities, the names of which are still known and commonly used by Torontonians.

Toronto has many groups and associations to deal with neighbourhood issues, and larger umbrella organizations organize events to deal with broader issues.

The former City of Toronto refers to the City of Toronto and its boundaries from 1967 to 1997. It is sometimes referred to as the "South" or "Central" district, and includes the "downtown core". Some of these names such as "The Fashion District" are (or were) used as marketing for the areas or by BIAs; this area is actually called "King-Spadina" by locals. Another example is the "Old Town of York", known also as "King and Parliament".

Many were recreated or branded to reconnect the areas with their past history, early beginnings, or even recent use and prominence. Some historical city 'wards' used in the 19th century are no longer used, St. David's, St. John's, St. Paul's, St. George's, St. Andrew's, and St. Patrick's wards. There was a ward named for the patron saint of each of the four British nationalities: English (St. George), Scottish (St. Andrew), Irish (St. Patrick), Welsh (St. David) (the first three survive as subway stops). St. Lawrence's Ward (named after patron saint of Canada and the river) remains, known today as "St. Lawrence").

For the purposes of geographic distinction, the neighbourhoods of the Former City are broken down into four subsections:

East York was formerly a semi-autonomous borough within the overall municipality of Metropolitan Toronto before East York, North York, York, Scarborough, Etobicoke and Toronto were amalgamated into the new "megacity" of Toronto in 1998. One of East York's claims to fame was that, before the amalgamation, it was Canada's only borough.

It is separated by the Don River from the former City of Toronto. Traditional East York is southeast of the river, and the neighbourhoods of Leaside, Bennington Heights and densely-populated Thorncliffe Park are northwest of the river. The heart of East York is filled with middle-class and working-class homes, with extensive high-rise developments along peripheral major streets and in Crescent Town and Thorncliffe Park.

Etobicoke is the western portion of the City of Toronto, Ontario, Canada, with an official population of 338,117 as measured by the 2001 Census and 334,491 people as of the 2006 Census. While it only contains 13% of Toronto's population, it occupies about 20% of its total land area. It is bordered on the south by Lake Ontario, on the east by the Humber River, on the west by the city of Mississauga and Toronto Pearson International Airport (though a small portion of the airport extends into Etobicoke), on the north by the city of Vaughan, and on the northwest by the City of Brampton.

Scarborough (2006 Census 602,575) is the eastern part of the City of Toronto, Ontario, Canada. It was named in 1796 by Elizabeth Simcoe, who was inspired by the Scarborough Bluffs, which reminded her of the white cliffs near her home in England. Initially a collection of rural villages, it has become a diverse urban community. Over 200 years it grew from a township to a city, but has been part of the eastern portion of Toronto since 1998. The name "Scarborough" is still used by local residents and recognized by Canada Post.

Scarborough has characteristics of a suburb of old Toronto, but retains much of its own character and flavour. Certain neighbourhoods in Scarborough are popular destinations for new immigrants to Canada, who bring their own culture to Scarborough. It includes some remote areas such as the Scarborough Bluffs and the Rouge River Valley. A journalist describing Toronto's suburbs commented on Scarborough's "lush greenery" and declared it to be greener than any other part of Toronto.

North York forms the central part of the northern half of Toronto, Ontario, Canada. As of the 2006 Census, it has a population of 635,370. The official 2001 census count was 608,288. Until 1998, it was the second-largest of six municipalities that comprised another larger municipal structure called Metropolitan Toronto. The previous year, the provincial Government of Ontario passed legislation to merge these municipalities into a single, new amalgamated City of Toronto. North York is one of the most diverse areas of Toronto, as it contains some of the richest areas of the city (The Bridle Path, Hogg's Hollow, Willowdale, York Mills, Lawrence Park) and some of the poorest (Jane and Finch, Flemingdon Park and Lawrence Heights).

York is a community in Toronto, Ontario, Canada. Formerly a separate city, it was one of six municipalities that amalgamated in 1998 to form the current city of Toronto. Its population, as of the 2001 census, was 150,255, the second smallest of the six former municipalities, yet it is one of the most ethnically diverse. By the 2006 census, the population had fallen somewhat to 143,255.