Oakville is located between Niagara Falls and Toronto, so there are several airports that serve the area. For international flights, the biggest airports are Toronto Pearson International airport, John C. Munro Hamilton International Airport and Buffalo/Niagara airport in New York.
Many Canadians make the trip to Buffalo and board planes there where airfares can be substantially lower because there are less levied taxes than at Canadian airports.
One particular flight saved our own family $600 to fly round trip to Orlando via Buffalo airport instead of Pearson. The taxes were just too high and the drive is not that much longer going to Buffalo than to Pearson from Oakville.
The success of the trip depends largely on how long the border crossing will take, but the Rainbow Bridge is usually very accommodating. The Lewiston Bridge seems to have the longest wait times.
Oakville airport transportation service is available by taxi, limo, shuttle bus or public transportation. There are also many parking lots catering to travellers near the airports. On a longer trip, or one where time is of the essence, it may make more sense to just take a cab or limo and not have to shuffle bags or wait for a connecting shuttle bus from the parking area to the terminal.
Oakville Ontario does not have any plans for an airport yet, but one never knows with all of the rapid expansion in the area including the new billion dollar Oakville Hospital and grounds. For now, Pearson, Hamilton or Buffalo airports are the most used air connection to Oakville with the smaller airports also accommodating flights. These smaller GTA airports include Toronto Island transportation from Billy Bishop Toronto City Airport and regional airports like Toronto Buttonville, Toronto Markham, Toronto Downsview, Brampton Airport and Burlington Air Park.
For a flight to or from the Oakville area, there are plenty of nearby airports serving the region and plenty of ground transportation options for the connection from Oakville to the airport.