It is the oldest and largest of the urban transit service providers in the Greater Toronto Area, with numerous connections to systems serving its surrounding municipalities.

The TTC sold Gray Coach Lines in 1990 to Stagecoach Holdings, which split the operation between Greyhound Canada and the government of Ontario three years later.

[citation needed] Deficits and government funding soared throughout the 1970s and 1980s,[9] followed by service cuts and a period of ridership decline in the 1990s, partly attributable to recession.

In 1997, the Progressive Conservative government under Premier Mike Harris implemented the "Common Sense Revolution" which, among other things, cut CA$42 million in provincial financing support for the Eglinton West subway line, and cut $718 million in municipal transit support, placing the entire burden of financing the system on municipalities and leaving the TTC with a $95.8 million/year funding shortfall.

[17] On August 12, 2020, the Province of Ontario promised $404 million for TTC operations to compensate for reduced ridership and revenue loss during the COVID-19 pandemic, with more funding to come later.

The TTC also runs Wheel-Trans, a paratransit service for the physically disabled with special low-floor buses designed to accommodate wheelchairs and to make boarding easier for ambulatory customers with limited mobility.

The full first phase of the route will span 19 kilometres (12 mi) across the city, from Mount Dennis in York to Kennedy station in Scarborough.

Streetcar routes are now focused on the downtown area, although two run farther from the core: one being on St. Clair Avenue, 6 kilometres (3.7 mi) from Lake Ontario on average, served by the 512 St. Clair streetcar route, and another on Lake Shore Boulevard (the western portion of 501 Queen), which runs through the Etobicoke district nearly to the city limits with Mississauga at Etobicoke Creek.

[61] In September 2023, the federal government imposed new licence conditions requiring that cellphone and data services be available on the entire subway network by the end of 2026 and that all mobile wireless carriers, including Telus and Bell, have access to it.

[65] As per Accessibility for Ontarians with Disabilities Act (AODA) guidelines, all surface vehicles and subway trains have been equipped with the on-board Automatic Next Stop Announcement System since February 2008.

A digital orange LED destination sign on streetcars and buses as well as the Toronto Rocket subway trains display the name of the upcoming streets/stations as the vehicle progresses on its route.

This feature allows boarding via the back doors at terminals, reduces the usage of paper transfers, and the need of operators to check for proof-of-payment.

With the exception of Greenwood, High Park, Jane, Old Mill, and Runnymede, all subway stations' off-street terminals are within the fare-paid area.

[70] All (with the exception of Highway 407 and Vaughan Metropolitan Centre stations, which only connect with regional buses) are located within the fare paid area and thus available only to TTC passengers.

TTC Head Office is in the William McBrien Building, located at 1900 Yonge Street at Davisville Avenue, which opened in 1957.

Special speed dial buttons have been installed on payphones in station Designated Waiting Areas that "link" the caller to a 24-hour crisis counselling service provided by Distress Centres of Toronto.

The negotiation between TTC and the Toronto Police Services Board took place in 2013 resulting in restored special constable status and peace officer authority.

Conceived in the late 1970s and fully implemented in 1991, it consists of a computer unit on board each bus and streetcar, called the Transit Radio Unified Microprocessor (TRUMP).

This is attached to a transponder receiver, which allows CIS operators to track the location of the vehicle using a computational system known as dead reckoning.

The TRUMP unit also allows vehicle and CIS operators to send and receive text messages for such things as short turns and route adjustments.

With the introduction of NextBus technology to provide real-time arrival information, the CIS has been updated to use a combination of GPS data and the previous dead reckoning (signpost-based) system.

In 2012, the TTC began research into transitioning from the outdated and antiquated CIS to a newer computer-aided dispatch (CAD) system.

[85] After extensive testing, deployment of VISION on vehicles in revenue service began in the summer of 2018, with plans to fully equip the entire bus and streetcar fleet by 2019.

They replaced older devices which communicated by the third rail, and are divided into separate systems representing their respective subway lines.

Most are operators, but the commission also employs supervisors, custodians and a wide range of skilled tradespeople who work on vehicles and critical subway and surface infrastructure.

[118] In March 2023, Jennifer McKelvie, the deputy mayor of Toronto, requested section 269.01 of the Canadian Criminal Code be amended to include assault against transit workers.

At the request of Mayor Rob Ford and Toronto City Council, on March 30, 2011, the Province of Ontario passed legislation classifying the TTC an essential service, which removed the employees' right to strike.

[121] On May 8, 2023, a Superior Court judge overturned the designation on the basis that the TTC did not meet the judicial definition of an "essential service" and therefore the restrictions on striking were unconstitutional.

In April, union members had voted overwhelmingly in favor of strike action if necessary, after their previous collective agreement expired at the end of March.

[125] The president of the Amalgamated Transit Union Local 113, Marvin Alfred, confirmed the next morning that a tentative agreement had been reached late the night before and that talks had continued until almost 4 a.m. "What we have right now is a deal," he said.