Cheap flights from St. Louis to Portland from $120

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 $296.

The cheapest day to depart on your flight to Portland is on a Tuesday when prices can be found for as low as $358. 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 Monday, with ticket prices averaging around $532.

The cheapest time of day to fly to Portland is in the afternoon when flights can be purchased for as low as $445. At noon is when there is more demand to fly to Portland, so prices are often more expensive at around $520 per ticket.

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 $364 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 $280 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.

You could potentially save up to 23% on your flight if you consider stops on a St. Louis to Portland flight.

As of July 2026, prices for St. Louis to Portland flights are approximately 24% more expensive when compared to flights at the same time last year.

Frontier is the most popular carrier operating from Lambert-St Louis to Portland

Alaska Airlines, Delta and United Airlines 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 35% 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.

Salt Lake City (SLC) was the most common stop: 36% of momondo users choosing 1-stop flights on this route connected there.

Flights via Dallas (DFW) offer the lowest average round-trip price of $243.

Flights connecting via Salt Lake City (SLC) have the shortest average one-way travel time: 5h 50m.

Salt Lake City (SLC) has the shortest average layover time for this route: 1h 05m.