$276 Cheap United flights San Francisco (SFO) to Ottawa (YOW)

Use the "Price (lowest to highest)" filter on Expedia to search for cheap United Airlines round-trip flights from $489 from SFO to YOW. Affordable one-way options from $276 are also on offer.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

Look for United Airlines flights from SFO to YOW about one month before you want to leave. The cheapest time to book an international flight is usually 18 to 29 days ahead of your travel date when you can save 17% versus booking four to five months in advance. No matter your fare class and itinerary, the best day of the week to book international airfare is usually Sunday. Friday is often the most expensive. Passengers booking on a Sunday can save an average of 17% compared to those who book on a Friday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.

Sort your results by "Morning" and "Early Morning" to see the earliest flights from SFO to YOW. Jetting off early means you're 20% less likely to experience cancellations.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.

Fly from SFO to YOW with United Airlines and you'll enjoy a host of benefits starting with a rewarding loyalty program. When you book through Expedia as a United Mileage Plus and One Key™ member, you may also earn OneKeyCash™* to use on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.