Cheap flights from St. Louis to Portland from $111

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 $289. 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 $594.

The cheapest time of day to fly to Portland is in the afternoon when flights can be purchased for as low as $401. 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 $355 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.

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

Delta, United Airlines and Alaska Airlines are the top three most popular airlines that fly to Portland from St. Louis according to our data. Delta is the first choice among our users, with 30% 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: 33% of momondo users choosing 1-stop flights on this route connected there.

Flights via Minneapolis (MSP) offer the lowest average round-trip price of $217.

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

Minneapolis (MSP) has the shortest average layover time for this route: 1h 00m.

As of May 2026, 1 flights take off from St. Louis and land in Portland each day. The most common flight departure time for this route is 5:00PM, with 80% of daily flights taking off in the afternoon.

The number of flights available between St. Louis and Portland is 7 per week as of May 2026. The most frequent departure day is Wed, with 29% of weekly flights leaving on this day.