Which means of transport to use Ontario?

From the airport to the city centre Ontario

There are two airports for international flights: Toronto (torontopearson.com) and Ottawa (yow.ca). Several other regional airports are served by airlines operating domestic flights within Ontario (although the fares are exorbitant), but also within Canada and to some American destinations.
The most efficient way to reach downtown from Toronto Pearson is the Union Pearson Express train ($12.35 Cdn one way, upexpress.com). Several TTC (ttc.ca) and Go Transit (gotransit.com/en) bus lines also connect the airport to the city of Toronto. From the Ottawa airport, you can take bus line 97 to Hurdman Station and then the O-Train to the centre ($3.60 Cdn one way, octranspo.com).
Of course, you will also find taxis (including Lyft and Uber), limousines, car rental companies and hotel shuttles at both airports.

Arrival by train Ontario

VIA Rail serves all of Canada from east to west (viarail.ca). Several cities are served along the line that runs through all of southwestern Ontario, from the Quebec border to Windsor. Other lines connect Ottawa, Niagara Falls, Stratford and Sarnia. From Toronto, Amtrak (francais.amtrak.com) allows you to travel to the United States, especially New York (1 departure per day). Although it is rather nice to travel by train, the fares are however higher than by bus.

Public transport Ontario

In addition to the VIA Rail train, which serves some regions of Ontario, the province benefits from an intercity bus network (which may be non-existent in some municipalities). Depending on the destination, the companies vary, but the main ones are Greyhound (greyhound.ca, also serves the United States), Megabus (ca.megabus.com, also serves Montreal, Quebec, and several American cities) and Ontario Northland (ontarionorthland.ca). The most frequent route is Toronto-Montreal with many departures per day, even at night. Several other companies provide regional and municipal transportation throughout the province.
Ontario also has a network of ferries, particularly in the Great Lakes region. While most are operated by Ontario Ferries (ontarioferries.com/en), there are other independent companies such as the Glenora-Adolphustown and Kingston-Wolfe Island ferries (mto.gov.on.ca/english/ontario-511/ferries.shtml), as well as the Toronto Island ferry service (torontoisland.com/ferry.php). Some ferries even run to the United States, such as the Pelee Island-Sandusky (Ohio) or Walpole Island-Algonac (Michigan) ferries.
The Greater Toronto Area is the most developed in terms of public transportation. The Toronto Transit Commission (ttc.ca) has a subway (75 stations on 4 lines) and an extensive network of buses and streetcars. There is also Go Transit (gotransit.com/en) which serves the Greater Toronto Area - and even beyond - by bus and train.

Bike, scooters & co Ontario

Toronto offers a bike share service, Bike Share Toronto (bikesharetoronto.com, several packages available). Other cities and towns offer this service, such as Hamilton (hamilton.socialbicycles.com) and Bobcaygeon (visitbobcaygeon.com/bike-sharing). Please note that there are no more bike share bikes in Ottawa-Gatineau, as VéloGo ceased operations in 2019. Until recently, Ontario legislation prohibited the use of public scooters on public roads, with the exception of a few pilot projects, including the Bird Company's pilot project in Toronto's Distillery Historic District in late summer 2019. But since January ¹, 2020, the provincial government has finally given cities and municipalities the choice of whether or not to allow these scooters on their territory, as part of a five-year pilot project. The project stipulates, however, that users must be at least 16 years old and that helmets must be worn.

With a driver Ontario

There are taxis almost everywhere in Ontario, even in the villages. Most of the companies in the larger cities have their own apps. The Uber service (uber.com/ca/en-ca/ride/) is also available across the province, while Lyft serves only Ottawa (lyft.com/rider/cities/ottawa-on) and the Greater Toronto Area (lyft.com/rider/cities/city-of-toronto-on). For longer distances, and to save on travel costs, it is also worth checking out centralized carpooling systems. Suggested companies are AmigoExpress (amigoexpress.com), Covoiturage.ca (carpool.ca) and Poparide (poparide.com).

By car Ontario

All regions of Ontario

- with the exception of the Far North - are connected to the entire province by the highway system. However, the distances are very great. French, Belgian and Swiss driver's licences are accepted for a period of up to three months; if you have one, you will need an international licence. If you wish to rent a car in Ontario, you must be 21 years of age, or 25 years of age for some models, and be in possession of a credit card. Gasoline, which is sold by the litre, is cheaper than in Europe or Quebec, and its price varies greatly from day to day and from company to company, much to the chagrin of Ontarians.

Theregulatory

speed limit is 100 km/h on highways (pilot projects increasing the speed to 110 km/h are underway on some highway sections), 90 km/h on the Trans-Canada Highway, 80 km/h on rural and country roads, and 50 km/h (sometimes less) in cities. The highway is still free except for the 407 north of Toronto (toll express). Seatbelts are mandatory for all passengers, as are car seats for younger people. The maximum permitted blood alcohol level is 0.08 g/l, with impaired driving resulting in a fine or more (frequent checks). In winter, motorways are generally cleared, but driving requires special reflexes and snow tyres are strongly recommended (but not compulsory).

Traffic rules and signs

are more or less the same as in Europe, with a few differences. Traffic lights are placed on the other side of the street intersection. There is no right-of-way in Ontario (first come, first served) and turning right at a red light is permitted everywhere except where there is a sign indicating that it is prohibited. Full stop is mandatory when following or crossing a stopped (almost always yellow) school bus with red flashers on. In Toronto, vehicles must also come to a complete stop at least 2 metres behind the back door of a stopped streetcar to ensure the safety of passengers.

As for parking

, no problem in the regions. But in the city, especially in Ottawa and Toronto, parking is often difficult and, before stopping your vehicle, you sometimes have to read three or four signs to know if you are on the right sidewalk, in the right time slot and thus avoid a ticket or, worse, impoundment! Also, check to see if there is a charge for parking, which is likely to be the case. Warning: it is strictly forbidden to park in front of a fire hydrant. If you make a mistake, rest assured that you will get your ticket within 5 minutes. Also, be aware that you can only park your vehicle in the direction of traffic. If you plan to stay in Toronto for several days, find out about temporary parking passes. They allow you to park your vehicle in a specific area for 24 hours, 48 hours or a week and the formalities are simple and can be done online (toronto.ca/services-payments/streets-parking-transportation/applying-for-a-parking-permit/temporary-on-street-parking). This will allow you to leave your vehicle parked during your stay, saving you a lot of headaches. Finally, it should be noted that every big city has its traffic and Toronto is particularly good at it. If you don't see traffic on Highway 401 or the Don Valley Parkway, pinch yourself and thank God for that, because it's pretty rare.