IAD - OPO

$258 Find Cheap Flights from Washington Dulles Airport to Porto

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Dulles Intl to Porto departing on 8/18. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy

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These are the airlines KAYAK users have selected most often from within our search results in flight searches from Washington, D.C. to Porto.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Washington, D.C. to Porto.
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Cheap Flights from Dulles Intl to Porto (IAD-OPO)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Dulles Intl to Porto that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Dulles Intl to Porto

Mon, Aug 18 - Tue, Aug 26
 Logo
10:20 pm - 10:25 pmIAD-OPO
19h 05m2 stops
 Logo
10:50 pm - 3:20 pmOPO-IAD
21h 30m2 stops
Mon, Aug 18 - Tue, Aug 26
 Logo
10:20 pm - 10:25 pmIAD-OPO
19h 05m2 stops
 Logo
10:50 pm - 8:50 pmOPO-IAD
27h 00m2 stops
Mon, Aug 18 - Tue, Sep 2
TAP AIR PORTUGAL Logo
10:20 pm - 5:00 pmIAD-OPO
13h 40m1 stop
TAP AIR PORTUGAL Logo
6:00 pm - 3:20 pmOPO-IAD
26h 20m1 stop
$490TAP AIR PORTUGAL
Find Deal
Mon, Nov 3 - Wed, Nov 19
United Airlines Logo
5:33 pm - 9:30 amIAD-OPO
10h 57m1 stop
United Airlines Logo
12:30 pm - 3:55 pmOPO-IAD
32h 25m2 stops
$491United Airlines
Find Deal
Wed, Oct 29 - Fri, Nov 7
Lufthansa Logo
11:55 pm - 11:45 pmIAD-OPO
19h 50m1 stop
Lufthansa Logo
6:00 am - 3:50 pmOPO-IAD
14h 50m1 stop
$492Lufthansa
Find Deal
Mon, Nov 3 - Wed, Nov 19
United Airlines Logo
5:33 pm - 9:30 amIAD-OPO
10h 57m1 stop
United Airlines Logo
12:35 pm - 8:57 pmOPO-IAD
13h 22m1 stop
$494United Airlines
Find Deal
Wed, Nov 5 - Wed, Nov 12
Lufthansa Logo
11:10 pm - 11:45 pmIAD-OPO
19h 35m1 stop
Lufthansa Logo
6:00 am - 3:50 pmOPO-IAD
14h 50m1 stop
$498Lufthansa
Find Deal
Mon, Sep 15 - Mon, Sep 22
TAP AIR PORTUGAL Logo
10:20 pm - 7:00 pmIAD-OPO
15h 40m1 stop
TAP AIR PORTUGAL Logo
6:00 pm - 3:20 pmOPO-IAD
26h 20m1 stop
$504TAP AIR PORTUGAL
Find Deal
Sun, Dec 7 - Thu, Dec 11
Iberia Logo
6:00 pm - 4:00 pmIAD-OPO
17h 00m1 stop
Iberia Logo
8:20 am - 4:30 pmOPO-IAD
13h 10m1 stop
$534Iberia
Find Deal
Wed, Sep 17 - Fri, Nov 14
Iberia Logo
4:35 pm - 7:35 amIAD-OPO
10h 00m1 stop
Iberia Logo
8:20 am - 3:45 pmOPO-IAD
12h 25m1 stop
$539Iberia
Find Deal
Booking Insights

KAYAK's insights & trends for Dulles Intl to Porto flights

Get data-powered insights and trends into flights from Dulles Intl to Porto to help you find the cheapest flights, the best time to fly and much more.

What’s the cheapest day of the week to fly from Washington Dulles Airport to Porto?

The average price of all round-trip flights from Washington, D.C. Dulles Intl Airport to Porto clicked on KAYAK for each day over the last 12 months.

If your flying dates are flexible, you should consider flying to Porto on a Sunday, as we generally find the cheapest rates on that day for this route. On the other hand, Friday is the most expensive day to fly from Washington Dulles Airport to Porto. For your return ticket, we recommend flying on a Monday and avoiding Wednesdays for the best deals.

What is the cheapest month to fly from Washington, D.C. Dulles Intl Airport to Porto?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Washington, D.C. Dulles Intl Airport to Porto, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Washington, D.C. Dulles Intl Airport to Porto is February, where tickets cost $543 (return) on average. On the other hand, the most expensive months are December and July, where the average cost of round-trip tickets is $995 and $883 respectively.

How far in advance should I book a flight from Washington, D.C. Dulles Intl Airport to Porto?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Washington, D.C. Dulles Intl Airport to Porto, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Washington, D.C. Dulles Intl Airport to Porto, you should book around 3 weeks before departure. For the absolute cheapest price, our data suggests you should book 18 weeks before departure.

Good to know

Low seasonFebruary
High seasonAugust
Cheapest flight$258
Best time to beat the crowds with an average 26% drop in price.
Most popular time to fly and prices are also 0% lower on average.
Flight from Washington Dulles Airport to Porto

When to book flights from Dulles Intl to Porto

Are your dates flexible? Find out the best times to travel from Dulles Intl to Porto based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking Washington Dulles Airport to Porto flights

  • How much luggage can I bring with me from Washington Dulles (IAD) to Porto (OPO)?

    The base fares on KLM, Delta, and TAP Air Portugal include one personal item and a carry-on free of charge. Any checked bags must be paid for separately. Another alternative would be to upgrade your ticket, which would increase your baggage allowance. The Standard fare with KLM includes one checked bag of up to 50 lbs. With Business class on American Airlines, you will have your carry-on and two checked bags included.

  • Can I fly with a service animal from Washington Dulles (IAD) to Porto (OPO)?

    On TAP Air Portugal, the dog must be a certified service animal (SVAN) with the appropriate paperwork and vaccination records. If they meet all the requirements, they are permitted to travel in the cabin, outside a carrier. You can request any special assistance services up to 48 hours before your trip.

  • Do I need a visa to fly to Porto?

    Portugal is a member of the EU, so American citizens and permanent residents do not need a visa to enter. Your stay in Portugal, or any other EU country, must not exceed 90 days and can only be for travel. You will be required to have a valid passport with at least 6 months of validity and at least one blank page for the stamps.

  • How do I get from Francisco Carneiro Airport (OPO) to the city center in Porto?

    If you are on a budget, then the metro is the most affordable way to get into the city. There is a station located directly at the airport and the trains run from 5 am to 1:15 am. It will take you around 30 minutes to reach the city center. Taxis are also readily available, the ride will cost around €20 to €30 ($22 to $33). For the most ease and comfort, you can book a private transfer from a service like Welcome Pickups.

  • What is the cheapest flight from Washington, D.C. Dulles Intl Airport to Porto?

    In the last 3 days, the lowest price for a flight from Washington, D.C. Dulles Intl Airport to Porto was $258 for a one-way ticket and $416 for a round-trip.

  • Do I need a passport to fly between Washington Dulles Airport and Porto?

    Yes

  • Which airports will I be using when flying from Washington Dulles Airport to Porto?

    Washington Dulles Airport and Porto are both served by 1 main airport. You will leave Washington Dulles Airport from Washington, D.C. Dulles Intl and will be arriving at Porto.

  • Which aircraft models fly most regularly from Washington Dulles Airport to Porto?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from Washington Dulles Airport to Porto?

    Star Alliance, oneworld, and SkyTeam are the airline alliances operating flights between Washington Dulles Airport and Porto, with Star Alliance being the most commonly used for this route.

  • What is the most popular layover when flying to Porto from Washington Dulles Airport?

    Lisbon is the most popular layover city among KAYAK users traveling from Washington Dulles Airport to Porto.

  • Which is the best airline for flights from Washington, D.C. to Porto, Delta or KLM?

    The two airlines most popular with KAYAK users for flights from Washington, D.C. to Porto are Delta and KLM. With an average price for the route of $797 and an overall rating of 8.0, Delta is the most popular choice. KLM is also a great choice for the route, with an average price of $690 and an overall rating of 7.8.

  • How does KAYAK find such low prices on flights from Washington Dulles Airport to Porto?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Washington Dulles Airport to Porto.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Washington Dulles Airport to Porto?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Porto from Washington Dulles Airport is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Washington Dulles Airport to Porto?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Porto with an airline and back to Washington Dulles Airport with another airline. Booking your flights between Washington Dulles Airport and OPO can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Washington Dulles Airport to Porto?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Porto from Washington Dulles Airport up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Washington, D.C. Dulles Intl Airport to Porto

  • All flights along this route from Washington Dulles Airport (IAD) to Porto (OPO) will have at least one stop. Amsterdam (AMS), Madrid (MAD), Lisbon (LIS), and Paris (CDG) are the most common layover cities.
  • Flights on KLM along this route will often have a long layover in their hub city, Amsterdam (AMS). All passengers can access the two Crown Lounges for free. If you upgrade to Business class, lounge access will be included.
  • All airlines give a 24-hour window from the time of booking in which you can modify your flight for free. You can keep your travel plans flexible by upgrading to Standard fare on KLM – which allows ticket changes for free, or their Flex fare – which is refundable if you need to cancel.
  • With TAP Air Portugal, you might be able to get a deal on your upgrade with their auction feature. Up to 36 hours before your flight, you can bid the amount you’re willing to pay and will receive a confirmation if accepted.
  • KLM welcomes families on board by ensuring they are seated together and providing special entertainment for the kids. They offer activity packs and special kid's meals to keep your little ones happy during the flight.

Reviews of the top 5 airlines serving from Dulles Intl to Porto

 
See real verified KAYAK customer reviews for airlines flying from Washington, D.C. to Porto. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Dulles Intl to Porto? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
DeltaOverall score based on 7959 reviews
7.9Comfort
7.9Entertainment
7.3Food
8.2Boarding
8.5Crew
Airline reviews

There was no problems, just a little uncomfortable with seats that do not lay back a little

8.0 ExcellentWillie, Jul 2025PHX - DTW
Read more Delta reviews

There was no problems, just a little uncomfortable with seats that do not lay back a little

Always good but we must do something about people in rows ahead of you that don't put their seats back up when they are suppose to. And It's rough to not be able to even lean over to get something out of my purse.

Flight was delayed, 30+ bags had to be gate checked. Crew were very friendly!

Everything was good until we were boarding our connection flight in Atlanta, we were told to gate check our carry-on, but when we got inside the plane, there was plenty of room in the overhead.

Did not know my son and I had different seating arrangements. He was fine, but it was disappointing.

Flight was canceled, and no effort was made to help with rebooking, no hotel vouchers, no car transportation and minimal food voucher and most places for food were closed by the time the voucher was given. Waited for 3 hours for bags. Simply the worst travel experience I have ever had

Food was surprisingly good but the WiFi was not great

this crew didn't care much. bumping carts into seats more times than i care to remember

Very late arrival at PWM. Late jet getting to ATL. Equipment problem with aircraft - could not get enough water onto plane., Another delay getting FAA approval for flight with bottled H2O. Not the crew’s problem.

Everything was fine except the entertainment was not working for half of the flight.

Our first flight was delayed so we missed our connecting flight. However it was easy to book a later flight on their app.

My flight was delayed by 6 hours then I missed BOTH of my connecting flights, I then had to stay in the AIRPORT at JFK because soooooo many people also suffered from missing flights and there was no hotels available. I would like to be compensated for this experience! I had to stay in the airport for over 16 hours!

The service was great. However the lounge only gets passing grade

Cabin crew professional, polite and friendly, boarding was seemless, but come on KLM surely you can do better than a pack of cheesy biscuits as an inflight snack

Cabin crew were excellent, very proffesional, polite and friendly, in flight snack was underwhelming, a packet of cheese biscuits, im sure KLM could run to a sandwich!

Legroom not all it could be, especially when the seat in front is reclined. Otherwise it was good, food and beverage were nice.

This portion of the flight was through Indigo. A local carrier. So all economy seating. No real service some refreshments for purchase standard economy stuff.

You should not have to pay for WiFi in business class

Overall very positive. Boarding was quick and organized. Cabin was clean and seats were reasonably comfortable. Cabin crew was excellent and the meals provided were also of good quality

This fight left ahead of time which meant it arrived early which was great. Staff were very professional, but as with all these Short hop Flights the food was a disappointing snack There was no entertainment on this flight, but I did not expect any

I learned that seating towards the end of plane that a line forms for the restroom and people use your chair as a hand railing, bumping your seat consistently. I was seated in the aisle. I think that next time if I am towards the back row I would want to sit in the middle or window seat.

The best airline I have ever travel , really good customer service, attention and service !!

United could have one single once of customer service. No human United employee would help me with the invalid mileage plus number, they said I had to speak with the computer.

I liked the choice of lemon ginger tea. I think stewardesses can be more considerate of older people needs.

We were given vouchers we couldn’t use with a 5.5 hour delay

I fly UAL 7-8 times per year. This flight was not up to snuff because it boarded very late "due to unexpected delays in restocking the plane" and yet Flight Aware showed the plane had landed some 10 hours earlier--so I think they could have planned accordingly. The FA's were nice but harried. The video system had to be rebooted 3-4 times. The food service was rather abrupt; they forgot my row and when I asked for my meal, they brought it with some impatience. Overall, the flight was fine, but the little details made it feel somewhat mundane and hurried.

I didn’t get on plane. Passport being processed by consulate with visa application. Tried to cancel through underpricer after purchasing cacelling for any reason. No dice, they are thieves.

When I booked it on Kayak it aaid that I wasn't allowed hamd luggage. I called United Airlines and it took them 6 minutes to figure out if I was allowed free hand luggage. Surely something that simple they should be able to tell me instantly.

We were delayed in Toronto on the tarmac for THREE hours with no clear indication as to why except that it was not a safety hazard. Pilot did apologize more than once but even he was unable to explain why exactly we were delayed. I overheard the stewards saying that the captain was very frustrated with the situation as well because he was not able to explain why except it had something to do with water supply or system on the aircraft and now we needed to wait for an engineer to approve the aircraft for flight. It was very frustrating and distressing as a passenger and we should have been given complimentary meals at the very least.

Flight was cramped with every seat taken. The food was fine, nothing crazy to write home about. The plane felt dated and needing some TLC, the button for the window shade didn't work and there were no AC outlets to use. When communicating with staff all except one nice lady never seemed happy to help me almost like I was bothering them when asked for things like a glass of water or a snack. The flight was overall fine. It did what was needed which is get me from point A to point B. But it certainly was not special. I don't expect much in economy but I believe economy on a host of other airlines is more memorable and better experience.

We flew TAP last October from Newark to Lisbon. The meal was bad. This flight had good food. Also, this flight was delayed. There were TAP employees waiting at Lisbon to make sure we made our connecting flight. I find the TAP website and app frustrating, but the service once we reached the airport was very good

The airport temperature at the airport and on the flight was too warm

Boarding too way too long. Biggest peeve: zero in-seat power in economy! No plug sockets, no USB ports. Plane was an A330, so not old.

boarding is so disorganized, i was literally appalled at the boarding experience

Comfortable but not Polaris or Delta comfort Business Class. Overall 7 out of 10

Tap air Portugal was the best I will traveling again with u guys. Thank u.

The long wait at JFK made the trip horrible. Also not having enough buses when we deplaned was annoying

Terrible! I had to cancel our flights due to my wife Carmen requiring an unexpected second cancer surgery. I first contacted orbitz about obtaining a credit due to medical interruption and orbitz directed me to TAP. I contacted TAP and the representative directed me back to orbitz and refused to even explain what TAP’s medical interruption policy was or how it worked—I wanted that information for a second call to orbitz. Terrible service at a particularly difficult time.

Food was edible, not great, and served by attendants who looked like they really were not happy working the flight. The section I was in was too warm making the 11 hour flight uncomfortable. Other areas on the plane were fine.

I’ve never had worse food in business class ever!

I described my experience in the previous window. I didn't realize that there would be another opportunity for this flight. Please look at my response in the previous window.

Boarding was 2 1/2 late no explanation Captain said he did not know why, but he rested at home for an extra couple of hours. Food was edible, Nothing more.

I liked the comfort of the plane. It was unexpected from past experiences.

BEWARE!!! Iberia changes your seats at random. I paid for a window seat and they changed it to one in the middle aisle resting against the bathroom- can’t lean back + hear every flush. This on a 11 hour flight.. There were families that were broken up with separate seats all over the plane. Lots of upset passengers showing their seat confirmation to the besieged and helpless airline steward. Also, the gluten free meal was tasteless.

Chair is very high. Your feet cannot touch the ground for 8 hours flight. It was a nightmare. Food was bad.

ground crew and check-in was pathetic - insisted on charging me for luggage even though the ticket said it was already included. They also accidentally sent my luggage through without a luggage tag and had to retrieve it. Generally, it was like a bad movie.

Moved the flight an hour later, were not reliable about confirmation, website didn't work, no gate information, boarding was a mad house. Flight itself was fine and short. Organization needs work.

The app on phone and the online check in is not good, it would not give me the option of Spain or Madrid City in the drop down menu and I couldn't move forward with online check in.

Flight was delayed 3 hours and 15 minutes. The delay caused me to miss my tour group due to arriving late.

As always a terrible experience. AA stole a day from my vacation days planned to be spent with my Family. Response: delays related to weather issues.

Everything you need to know for your flight from Dulles Intl to Porto

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