Cheap flights from St. Louis to Porto from $709
This is the cheapest round-trip flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Porto departing on 4/8. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
Deals available from 900+ travel sites.
Big names and deals
Big names and deals
Search 100s of travel sites to compare prices.Filter for what you want
Filter for what you want
Free Wi-Fi? Stopover? Instantly customize your results.Trusted and free
Trusted and free
We’re completely free to use - no hidden charges or fees.Price Alerts
Price Alerts
Not ready to book? to track prices.Find the cheapest flights from St. Louis to Porto
Cheap round-trip flights
Cheap one-way flights
Lufthansa flights from St. Louis to Porto
Our best Lufthansa deals on St. Louis to Porto flight tickets
United Airlines flights from St. Louis to Porto
Our best United Airlines deals on St. Louis to Porto flight tickets
See travel insights to Porto from
How to get the cheapest flight ticket from St. Louis to Porto
Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip
What is the cheapest month to fly to Porto?
The month of November is, on average, the cheapest month to fly to Porto from St. Louis, with most prices found around $633. If you aren’t able to travel during the month of November, then book flights to Porto from St. Louis during February instead. Flights to Porto in February, while not as cheap as those in November, still average around $706.
What is the cheapest day to depart on your flight to Porto?
The cheapest day to depart on your flight to Porto is on a Thursday when prices can be found for as low as $752. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Friday because tickets tend to average around $1,465. These prices are subject to change though, so be sure to set up a Price Alert for flights to Porto.
When to book flights from St. Louis to Porto
Cheap St. Louis to Porto (STL to OPO) flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from St. Louis to Porto
How far is Lambert-St Louis to Porto by plane?
There are 4156.0 mi between Lambert-St Louis and Porto. A reasonable flight in good conditions will take 11h 01m.
When did momondo last update prices for flights from Lambert-St Louis Airport to Porto Airport?
Prices for flights from Lambert-St Louis Airport to Porto Airport are refreshed on a daily basis.
How many operators does momondo search for flights from Lambert-St Louis Airport to Porto Airport?
The number of operators available for flights from Lambert-St Louis Airport to Porto Airport is 2 as of March 2025.
How old do you have to be to fly from Lambert-St Louis Airport to Porto Airport?
The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Lambert-St Louis Airport to Porto Airport.
What documentation or ID do you need to fly to Porto Airport?
The travel and health documents you'll need for your trip to Porto Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Porto Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.
What is the most popular airline from St. Louis to Porto?
Based on momondo bookings for this flight route, the most popular airline on flight routes from St. Louis to Porto is United Airlines (78% of total bookings). The next most popular airline is Delta (22%).
Best airlines flying from St. Louis to Porto
Compare and see reviews for airlines that fly from St. Louis to Porto with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $713 | Free Cancellation | Rating 8.0 7,973 reviews | |||
| PriceFrom $752 | Free Cancellation | Rating 7.4 8,631 reviews |
Traveling to a place near Porto?
Book flights to Porto if you plan to visit one of these locationsWhy use momondo?
Why should I use momondo to find a flight deal from St. Louis to Porto?
Finding the right flight to Porto from St. Louis is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to Porto quick and easy, saving you time and money.
Can I find flights from St. Louis to Porto with flexible booking policies on momondo?
All flight searches from St. Louis to Porto on momondo can be filtered to show those which offer flexible booking policies.
How can momondo help me find flights from St. Louis to Porto?
momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from St. Louis to Porto.
I’m not ready to book a flight from St. Louis to Porto right now. Can momondo alert me if prices change?
Price alerts on flights to Porto from St. Louis are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.