Air Canada has round-trip flights from Portland (PDX) to Toronto (YYZ) for $240-$260, NONSTOP. Flights July to August. Extended weekends available. Origin/Destination reversible.
Some sites are selling this as “two separate one-ways” in order to lower the price by to avoiding certain airport and border taxes. Beware if you plan on booking that way, since you may have to pay those taxes anyway when you arrive at the border.
We are ignoring Westjet’s slightly cheaper fares due to the additional fees and limitations of their “UltraBasic” fare.
Some small OTAs on Skyscanner and Google have this for as low as $232; which is cheaper than the airline. If you plan on booking there, beware of any site that charges a fee to cancel a ticket within the 24-hour “free” period. Use unknown booking sites at your own risk.
Click for more details and booking links Nonstop Flights: Portland to/from Toronto $232-$260 r/t [July-August] – Air Canada