Bus service in Toronto began in 1849, when the first public transport system in Toronto, the Williams Omnibus Bus Line, was launched.
The service began with a fleet of six horse-drawn stagecoaches.
After ten years, the use of streetcars were introduced in the city as the Toronto Street Railway (TSR) was established in 1861.
After a year of competition between the two companies, the TSR had surpassed Williams Omnibus Line in ridership.

Until 1921, several private and publicly owned transport systems were established and ended up being merged into one another or abandoned.
Electric streetcars were widely used in Toronto and surrounding settlements during the new century.
After the establishment of the Toronto Transportation Commission (TTC) (predecessor of the Toronto Transit Commission (also having the acronym of TTC) until 1954), streetcar routes were taken over from predecessors in 1921.
It ran bus routes by using motor buses for the first time in the city.
The TTC also experimented the use of trolley buses from 1922 to 1925.
Gray Coach, an intercity bus line by the TTC, began operation in 1927.
As the coach service increased in ridership, the TTC built the Toronto Coach Terminal.
By 1933, the TTC introduced the local bus and streetcar stop design, a white pole with a red band on the top and bottom.
Throughout the 1930s and 1940s, the city began replacing various street railway routes extending to surrounding municipalities with bus routes.
Between 1947 and 1954, the TTC acquired new trolley buses and converted several streetcar routes to use them.

A few private bus operations existed alongside the Toronto Transportation Commission, including Hollinger Bus Lines in East York (1921–1954), Danforth Bus Lines in North Toronto and King City and its subsidiaries North York Bus Lines in North York and Toronto Bus lines which operated north and east of Toronto (1926–1954), West York Coach Lines in York (1946–1954), Hollinger Bus Lines, which operated in East York and Scarborough, as well as a route to Mount Albert and Roseland Bus Lines which served York and had a route from Weston to Woodbridge (1925–1954).
All services were taken over by the TTC on 1 January 1954, when it became the sole public transit operator in the newly formed Metropolitan Toronto.

In 1966, plans were made to replace all streetcar routes with buses in the next 20 years.
The plan was cancelled in 1972 and streetcar routes were rebuilt.
Two years before the cancellation of the plan, GO Transit was established by the Government of Ontario with Gray Coach serving as its operator for most of its routes.
The TTC operated its first dial-a-bus services under GO Transit in 1973.
In 1975, the first paratransit service, Wheel-Trans, was established by a private operator.
The TTC also began using minibuses for minor routes, which would be replaced by regular buses by 1981.

In 1987, the TTC implemented the Blue Night Network, an expansion of its overnight services using buses and streetcars.
The following year, the TTC took over Wheel-Trans services.
In 1989, the TTC began using buses fuelled by compressed natural gas (CNG).
The TTC sold Gray Coach Lines to the Scotland-based Stagecoach Group in 1990, while also introducing "community buses", providing minibus service in a few residential neighbourhoods.
In 1993, the TTC ceased the use of electric trolley buses.
Accessibility expanded to regular buses in 1996 with the use of lift-equipped buses.
This was further improvised two years later when low-floor buses were added to the fleet.
Bus service in Toronto began in 1849, when the first public transport system in Toronto, the Williams Omnibus Bus Line, was launched. The service began with a fleet of six horse-drawn stagecoaches. After ten years, the use of streetcars were introduced in the city as the Toronto Street Railway (TSR) was established in 1861. After a year of competition between the two companies, the TSR had surpassed Williams Omnibus Line in ridership.
Until 1921, several private and publicly owned transport systems were established and ended up being merged into one another or abandoned. Electric streetcars were widely used in Toronto and surrounding settlements during the new century. After the establishment of the Toronto Transportation Commission (TTC) (predecessor of the Toronto Transit Commission (also having the acronym of TTC) until 1954), streetcar routes were taken over from predecessors in 1921. It ran bus routes by using motor buses for the first time in the city. The TTC also experimented the use of trolley buses from 1922 to 1925. Gray Coach, an intercity bus line by the TTC, began operation in 1927. As the coach service increased in ridership, the TTC built the Toronto Coach Terminal. By 1933, the TTC introduced the local bus and streetcar stop design, a white pole with a red band on the top and bottom. Throughout the 1930s and 1940s, the city began replacing various street railway routes extending to surrounding municipalities with bus routes. Between 1947 and 1954, the TTC acquired new trolley buses and converted several streetcar routes to use them.
A few private bus operations existed alongside the Toronto Transportation Commission, including Hollinger Bus Lines in East York (1921–1954), Danforth Bus Lines in North Toronto and King City and its subsidiaries North York Bus Lines in North York and Toronto Bus lines which operated north and east of Toronto (1926–1954), West York Coach Lines in York (1946–1954), Hollinger Bus Lines, which operated in East York and Scarborough, as well as a route to Mount Albert and Roseland Bus Lines which served York and had a route from Weston to Woodbridge (1925–1954). All services were taken over by the TTC on 1 January 1954, when it became the sole public transit operator in the newly formed Metropolitan Toronto.
In 1966, plans were made to replace all streetcar routes with buses in the next 20 years. The plan was cancelled in 1972 and streetcar routes were rebuilt. Two years before the cancellation of the plan, GO Transit was established by the Government of Ontario with Gray Coach serving as its operator for most of its routes. The TTC operated its first dial-a-bus services under GO Transit in 1973. In 1975, the first paratransit service, Wheel-Trans, was established by a private operator. The TTC also began using minibuses for minor routes, which would be replaced by regular buses by 1981.
In 1987, the TTC implemented the Blue Night Network, an expansion of its overnight services using buses and streetcars. The following year, the TTC took over Wheel-Trans services. In 1989, the TTC began using buses fuelled by compressed natural gas (CNG). The TTC sold Gray Coach Lines to the Scotland-based Stagecoach Group in 1990, while also introducing "community buses", providing minibus service in a few residential neighbourhoods. In 1993, the TTC ceased the use of electric trolley buses. Accessibility expanded to regular buses in 1996 with the use of lift-equipped buses. This was further improvised two years later when low-floor buses were added to the fleet.
Toronto Transit Commission bus system