Cheap flights from St. Louis to Portland from $122

The cheapest month to fly to Portland from St. Louis is in January. Flight prices, which tend to average around $292, are often lower during this time because this is during the off-season. If you don’t want to visit Portland in January, then you should wait until September to fly from St. Louis, when ticket prices are also cheap, with an average price of $304.

The cheapest day to depart on your flight to Portland is on a Tuesday when prices can be found for as low as $377. This is often the case because there is less demand to fly during this day of the week. The most expensive day to fly to Portland is Sunday, with ticket prices averaging around $484.

Fly from Lambert-St Louis to Portland for the best Lambert-St Louis - Portland flight prices

You are more likely to see cheaper flights to Portland from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Portland for around $368 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Portland from St. Louis for as low as $283 on momondo.

There are 3 cabin classes available to choose from on St. Louis to Portland flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

As of August 2026, prices for St. Louis to Portland flights are approximately 17% cheaper when compared to flights at the same time last year.

Alaska Airlines and Delta are the most popular carriers operating from Lambert-St Louis to Portland

Alaska Airlines, United Airlines and Delta are the top three most popular airlines that fly to Portland from St. Louis according to our data. Alaska Airlines is the first choice among our users, with 42% of people opting to fly with this airline when traveling to Portland. Keep in mind that there are 6 different airlines that fly to Portland on a routine basis, so you have a few additional options to choose from.

Denver (DEN) was the most common stop: 50% of momondo users choosing 1-stop flights on this route connected there.

Flights via Seattle (SEA) offer the lowest average round-trip price of $248.

Flights connecting via Denver (DEN) have the shortest average one-way travel time: 7h 04m.

Dallas (DFW) has the shortest average layover time for this route: 1h 19m.