The Greater Toronto Area was home to a number of First Nations (Indigenous) groups who lived on the shore of Lake Ontario long before the first Europeans arrived in the region. At various times the Neutral, Seneca, Mohawk and Huron nations were living in the vicinity. The Mississaugas arrived in the late 17th or early 18th century, driving out the Iroquois.

By the 17th century, the area was a crucial point for travel, with the Humber and Rouge River providing a shortcut to Lake Simcoe and the upper Great Lakes. These routes were known as the Toronto Passage. The area would later become very crucial for its series of trails and water routes that led from northern and western Canada to the Gulf of Mexico. Known as the "Toronto Passage", it followed the Humber River, as an important overland shortcut between Lake Ontario, Lake Simcoe and the upper Great Lakes. For this reason area became a hot spot for French fur traders. The French established two trading forts, Magasin Royal in the 1720s, although abandoned within the decade and Fort Rouillé in the 1750s, which was burnt down and abandoned in 1759 by the French garrison, who were retreating from invading British forces.

The first large influx of European settlers to settle the region were the United Empire Loyalists arriving after the American Revolution, when various individuals petitioned the Crown for land in the Toronto area. In 1787, the British negotiated the purchase of more than a quarter million acres (1,000 km²) of land in the area of Toronto with the Mississaugas of New Credit.

The Greater Toronto Area is classified as a humid continental climate. In winter, which begins in December and ends in March, typical high temperatures will range from −5 to 2 °C (23 to 36 °F) and low temperatures from −11 to −6 °C (12 to 21 °F). Occasional cold spells hold daytime highs below −10 °C (14 °F) for several days, while low temperatures sometimes drop below −18 °C (0 °F). Mild spells are also a feature of Toronto's winter, with temperatures occasionally surpassing 5 °C (41 °F) for several days. Spring is short and often mild, although snow sometimes falls as late as April. Summer is warm, sometimes hot and humid and begins in June and ends in late September. High temperatures typically range from 24 °C (75 °F) to 31 °C (88 °F) while low temperatures hover around 15 °C (59 °F) in the suburbs and 18–20 °C (64–68 °F) downtown and near the lake. Although fairly sunny, summers do feature occasional heavy, thundery showers. Heat wave conditions featuring temperatures between 32 °C (90 °F) and 35 °C (95 °F) are not uncommon. Temperatures are lower near the lake and higher inland. Although rare, the mercury sometimes rises above 38 °C (100 °F). Autumn alternates between wet and dry periods. Temperatures fall sharply in November and by December, cold and snowy weather is common. The summer of 2016 was one of the hottest summers on record with 38 days at or above 30 °C (86 °F).

• Toronto Pearson International Airport (YYZ ^IATA) is the area's major international airport, in Mississauga. It is well-served by many North American and international airlines.
• Billy Bishop Toronto City Airport (YTZ ^IATA) is on the Toronto Islands, connected to the Harbourfront by ferry and pedestrian tunnel. It is much closer to downtown Toronto, but there are far few airlines and flight options than Pearson. Airlines mostly serve airports in Ontario, Quebec and Atlantic Canada, as well as Boston, Chicago, New York-Newark, and Washington DC.

See also: Toronto#By bus

• Flixbus, Megabus, Ontario Northland, Red Arrow, and Rider Express provide intercity service focused on the Toronto Union Station Bus Terminal. Some trips also serve Mississauga, North York, or Scarborough.
• GO Transit provides regular regional transit services by bus, extending to a few locations outside the region. Major terminals are in downtown Toronto, North York, Mississauga, Burlington, and Oshawa.

See also: Rail travel in Canada, GO Transit

Trains serving the Greater Toronto generally use Toronto Union station as their terminus station.

• Amtrak, ☏ +1-215-856-7924, toll-free: +1-800-872-7245. Operates trains throughout the United States of America. (updated Jul 2022) Amtrak operates the Maple Leaf train service daily between Toronto and New York City, in partnership with VIA Rail Canada. Stops between Toronto and New York City include in Oakville, Burlington, Grimsby, St. Catharines, Niagara Falls (Ontario), Niagara Falls (New York), Buffalo, Buffalo (Depew), Rochester, Syracuse, Rome, Utica, Schenectady, Albany (Rensselaer), Hudson, Rhinecliff, Poughkeepsie, Croton-on-Hudson, and Yonkers.
• VIA Rail Canada, toll-free: +1-888-842-7245. Operates many intercity trains across Canada. (updated Apr 2022) See Rail travel in Canada for more details. Train routes operating to Toronto:
  • Between Montreal and Toronto including stops in Dorval, Cornwall, Brockville, Kingston, Belleville, Cobourg, and Oshawa.
  • Between Ottawa and Toronto including stops in Smiths Falls, Brockville, Gananoque, Kingston, Napanee, Belleville, Trenton, Cobourg, Port Hope, and Oshawa.
  • Between Sarnia and Toronto including stops in London, St. Marys, Stratford, Kitchener, Guelph, Georgetown, Brampton, and Mississauga.
  • Between Vancouver and Toronto on The Canadian, which operates several trips per week.
  • Between Windsor and Toronto including stops in Chatham, London, Ingersoll, Woodstock, Brantford, Burlington, and Oakville.
• GO Transit, ☏ +1-416-869-3200, toll-free: +1-888-438-6646. GO Transit operates 7 commuter rail lines radiating from Toronto serving smaller cities within and near the Greater Toronto Area. The lines have various service levels varying from all-day service to limited mid-day service to only rush-hour, peak-direction service. Most fares can be paid by credit, debit or Presto card. (updated May 2022)

The entire region is connected to the rest of Ontario by modern highways and major roads. Highway 401 connects Windsor with Quebec, through Halton, Peel, Toronto and Durham. Highway 400 is the route to cottage country, running north to Barrie and beyond. Many routes are congested even outside of rush hour.

GO Transit operates the commuter transit services serving municipalities within and near the GTA. It operates 7 commuter rail lines, radiating from Union Station at the base of Toronto's financial district. The Lakeshore West and Lakeshore East lines operate every day from 6AM to 1AM between Burlington and Pickering. Three other lines have limited mid-day service to Unionville (Markham), Aurora and Brampton. Otherwise, all other GO rail destinations are commuter-oriented, inbound to Union Station during morning rush hour and outbound during evening rush hour. GO buses often complement GO Transit rail service for destinations or time periods not covered by GO trains. Many GO bus route originate at four stations along subway Line 1 Yonge–University; they are Union Station, Yorkdale, York Mills and Highway 407.

There are various local transit operators to serve the different municipalities within the GTA. The Toronto Transit Commission (TTC) is the largest, running all the buses, streetcars and subways within Toronto. York Region Transit operates buses in York Region, to the north of Toronto. YRT also runs 6 bus rapid transit (BRT) lines, known as VIVA; most connect to a TTC subway station. Durham Region Transit operates local bus service in Durham Region, east of Toronto, serving cities and towns between Toronto and Oshawa. MiWay operates bus service in Mississauga to the west of Toronto. Most of its services are centred on the Square One shopping centre and many of its routes connect to subway Line 2 Bloor–Danforth at Islington station. Also, to the west of Toronto, there are three small cities (Brampton, Oakville and Burlington) that have their own local bus systems.

Toronto International airport (YYZ ^IATA) in Mississauga is served by GO commuter buses (to Yorkdale/York Mills), Mississauga, Brampton and Toronto local buses and a TTC bus (at regular fare, $3.25) directly to TTC's Kipling subway station in Toronto/Etobicoke. There's also the UP Express, a train direct to Union Station in Toronto/Downtown with on-board wi-fi (cash fare $12.35, or $9.25 with a Presto card, credit card or mobile app payment, as of Mar 2021).

While it is expensive to park in downtown Toronto, driving remains convenient for many areas of the GTA (or necessary in the outskirts of GTA). Pay attention that Highway 407 is tolled. They charge based on distance and time of driving (highest charge during weekday rush hour, lowest at night and on weekends). You do not see toll booths. All tolls are charged electronically. A toll-free alternative to Highway 407 is Highway 401.

Canada's history is woven into the GTA's oldest neighbourhoods. Monuments, protected buildings, and historic markers turn these areas into destinations for seeing what life was like several generations ago. Toronto's Old Town preserves some of the region's oldest buildings still accessible to the public, such as the St. Lawrence Market, the Cathedral Church of St. James, and various buildings in the Distillery District. Just north of Downtown is Casa Loma, an impressive castle completed in 1914, open for tours and overlooking the city from a small ridge. Head further north to North York to see Black Creek Pioneer Village, a living museum near York University.

In Toronto's suburbs, Old Oakville, has a few small buildings restored to the pioneer era, with costumed interpreters. Parkwood Estate Gardens in Oshawa is a grand private estate featuring architectural, landscape and interior designs of the early 20th-century English Arts and Crafts period. It operates as a museum and public garden. Unionville Main Street historic village developed in the 1840s in what was then Markham Township. As typical of a small village, it boasts numerous quaint period buildings in an idyllic surrounding.

The Art Gallery of Ontario and the Royal Ontario Museum are among the largest in the country, with permanent collections and special exhibitions that could take your entire day to explore in detail.

In Vaughan, the McMichael Canadian Art Gallery focuses on Canadian art, including the Group of Seven and First Nations, Métis, and Inuit artists. In Brampton, the Peel Art Galley Museum and Archives presents local historic and contemporary art, and international pieces of interest to the communities of Peel while museum artifacts tell the stories of the towns and communities to the west of Toronto.

The Toronto Zoo occupies a huge area of land near Rouge Park in Scarborough, home to many exotic animals and Canadian wildlife. Toward the western edge of the GTA in Burlington, the Royal Botanical Gardens preserves over 900 hectares (2,200 acres) of nature sanctuary that forms part of the Niagara Escarpment Biosphere Reserve. With several gardens, an arboretum and conservatory, the complex is one of the largest botanical gardens in North America.

Toronto has a busy live theatre calendar, including locally produced shows, shows being prepared for Broadway, and touring shows. Venues are focused in the Entertainment District and Yonge-Dundas. Smaller theaters located in the suburbs also offer quality programming throughout the year, including many shows for children. North of Toronto, York Region is home to the Richmond Hill Centre for the Performing Arts. Peel has the Brampton Rose Theatre and Mississauga Living Arts Centre, and Halton has the Oakville Centre for Performing Arts. These venues also host each city's local symphony orchestra, as well as visiting musical performers.

The Toronto International Film Festival, over 10 days in early September, is one of the leading film festivals in the world. Unlike the Cannes Film Festival, TIFF is open to film fans, showing a massive 245 films to almost half a million movie-goers in 2019. Through the rest of the year, the festival's headquarters at the TIFF Bell Lightbox is open to the public for screenings of Canadian and international cinema, special exhibits, and research at the provinces' film library

Toronto is represented in most of North America's major sports leagues, including the Toronto Blue Jays (baseball), the Toronto Maple Leafs (hockey), the Toronto Raptors (2019 National Basketball Association champions), the Toronto Argonauts (Canadian football), and Toronto FC (soccer/association football). Woodbine Raceway is a major horse racing venue in Toronto/Etobicoke.

Other professional or regional leagues can be a great way to experience popular Canadian sports up-close, or when the major leagues are sold old. For Hockey, check out the Toronto Marlies, (playing in the American Hockey League), the Mississauga Steelheads or Oshawa Generals (both in the Ontario Hockey League). The Raptors 905 play basketball in Mississauga, while Lacrosse is played by teams in Oakville and Whitby.

Rouge Park is a 63-km² urban national park crossing the boundaries of the cities of Toronto, Markham and Pickering and the Township of Uxbridge. It has 13 hiking trails ranging from 500 m to 5 km and from easy to challenging.

Public beaches, playgrounds and picnic spots dot the Lake Ontario waterfront. The Toronto Islands are most central, but feel a world away thanks to the short ferry ride from the city and the panoramic view over the lake. The Burlington Beachway near the Hamilton border is popular among families in the west end of the GTA. The Great Lakes Waterfront Trail runs parallel to the shoreline connecting many of the parks together, but note some segments of the trail are on-road and shared with traffic.

Further from the lake, the Niagara Escarpment touches the GTA in Milton, providing the region with access to the Bruce Trail, scenic look-outs at Rattlesnake Point, and a small ski and snowboard hill popular with beginners at Glen Eden. In Vaughan, the Kortright Centre for Conservation provides 16km of trail through forests, marshland and meadow, and runs nature and environmental education programs for children and adults. Events range from demonstrating maple syrup production to displaying renewable energy technology. Uxbridge offers winter sports and hiking through the Oak Ridges Moraine, in the east reaches of the region.

Canada's Wonderland is a Cedar Fair theme park in Vaughan.

The Canadian National Exhibition is an annual agricultural exhibition and carnival that combines food, technology, gardening, live entertainment, arts, sports, shopping and the Canadian National Airshow. Held each year in late-August until the first Monday in September, it has grown since 1879 to become a modern end-of-summer tradition not just for residents of Toronto, but for families throughout Ontario. For a taste of the small town fairs that once defined spring or summer throughout the rural parts of the GTA, head to the fairgrounds in Whitby (June) or Milton (September).

The Toronto Caribbean Carnival (formerly known as Caribana) is a huge Caribbean festival held over three weeks in July in early August, with parades and parties and music and dancing and food. It is the largest festival of Caribbean culture in North America, drawing over a million people, and serving as a reunion for people of the Caribbean diaspora in North America.

A huge LGBT Pride Festival and parade, held usually near the end of June, brings several hundred thousand people to downtown Toronto.