IAD - OPO

$336 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 5/17. 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, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights 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.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Washington, D.C. to Porto.
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 23% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Everything you should know

Cheapest round-trip
$589
Typical prices: $727-$591
Turkish Airlines
Tue 4/14Fri 4/24
IAD - OPO • 1 stop
Cheapest one-way
$336
Typical prices: $467-$657
Multiple Airlines
Sun 5/17
IAD - OPO • 2 stops
Top airlines
Cheapest • from $594 (round-trip)
Best reviews • 7.9 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Nonstop flights
Not available
There are currently no direct flights between Dulles Intl and Porto. You'll need at least 1 connection.
Insights
Insights
Insights
Insights
Top layover airports
Cheapest • Avg $318 (round-trip)
Shortest trip • 10h 15m (one-way)
Insights
Insights
Insights
Insights
When to book
in advance
Our data shows that travelers who book at least 3 weeks in advance save around 36% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 25% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to Porto!
Flight Deals
Booking Insights
Flight Deals

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

Tue, Apr 14 - Fri, Apr 24
Turkish Airlines Logo
9:45 pm - 3:40 pm
IAD
-
OPO
36h 55m
1 stop
Turkish Airlines Logo
10:40 am - 7:50 pm
OPO
-
IAD
38h 10m
1 stop
$589Turkish Airlines
Sat, Apr 25 - Thu, May 7
Turkish Airlines Logo
9:45 pm - 11:30 pm
IAD
-
OPO
20h 45m
1 stop
Turkish Airlines Logo
6:10 am - 7:50 pm
OPO
-
IAD
18h 40m
1 stop
$594Turkish Airlines
Mon, Apr 13 - Mon, Jun 8
Turkish Airlines Logo
9:45 pm - 9:45 am
IAD
-
OPO
31h 00m
1 stop
Turkish Airlines Logo
6:30 am - 7:50 pm
OPO
-
IAD
18h 20m
1 stop
$598Turkish Airlines
Tue, Aug 18 - Fri, Aug 28
TAP AIR PORTUGAL Logo
10:35 pm - 5:10 pm
IAD
-
OPO
13h 35m
1 stop
TAP AIR PORTUGAL Logo
9:00 am - 3:10 pm
OPO
-
IAD
11h 10m
1 stop
$604TAP AIR PORTUGAL
Wed, Apr 15 - Wed, Apr 22
Turkish Airlines Logo
1:20 pm - 3:40 pm
IAD
-
OPO
21h 20m
1 stop
Turkish Airlines Logo
4:40 pm - 7:50 pm
OPO
-
IAD
32h 10m
1 stop
$606Turkish Airlines
Sun, Apr 12 - Wed, Apr 29
Turkish Airlines Logo
1:20 pm - 3:50 pm
IAD
-
OPO
21h 30m
1 stop
Turkish Airlines Logo
10:45 am - 11:35 am
OPO
-
IAD
29h 50m
1 stop
$607Turkish Airlines
Wed, Aug 19 - Fri, Aug 28
TAP AIR PORTUGAL Logo
5:45 pm - 10:10 am
IAD
-
OPO
11h 25m
1 stop
TAP AIR PORTUGAL Logo
9:00 am - 3:10 pm
OPO
-
IAD
11h 10m
1 stop
$608TAP AIR PORTUGAL
Sun, Aug 16 - Sun, Aug 30
TAP AIR PORTUGAL Logo
10:35 pm - 3:00 pm
IAD
-
OPO
11h 25m
1 stop
TAP AIR PORTUGAL Logo
6:00 pm - 3:10 pm
OPO
-
IAD
26h 10m
1 stop
$613TAP AIR PORTUGAL
Wed, Apr 15 - Sat, May 2
Turkish Airlines Logo
1:20 pm - 3:40 pm
IAD
-
OPO
21h 20m
1 stop
Turkish Airlines Logo
4:40 pm - 11:35 am
OPO
-
IAD
23h 55m
1 stop
$616Turkish Airlines
Tue, May 5 - Tue, May 12
Turkish Airlines Logo
9:45 pm - 10:00 am
IAD
-
OPO
31h 15m
1 stop
Turkish Airlines Logo
4:50 pm - 11:35 am
OPO
-
IAD
23h 45m
1 stop
$617Turkish Airlines
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.

How much is a round-trip flight from Washington, D.C. Dulles Intl Airport to Porto?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Washington, D.C. Dulles Intl Airport to Porto departing in April.

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 October, where tickets cost $543 (return) on average. On the other hand, the most expensive months are December and May, where the average cost of round-trip tickets is $913 and $852 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, which saves you about 36% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 24 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$336
Best time to beat the crowds with an average 16% drop in price.
Most popular time to fly with an average 14% increase in price.
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 $336 for a one-way ticket and $594 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?

    oneworld, SkyTeam, and Star Alliance are the airline alliances operating flights between Washington Dulles Airport and Porto, with oneworld 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 $1,030 and an overall rating of 7.9, Delta is the most popular choice. KLM is also a great choice for the route, with an average price of $751 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.
7.9
DeltaOverall score based on 8330 reviews
8.1Boarding
8.5Crew
7.8Entertainment
7.2Food
7.9Comfort
Airline reviews

The first class flight attendant was awful to everyone. Very rude; no customer service. She should not be working in first class.

4.0 OkayKacie, Mar 2026
EWR - BOS
Read more Delta reviews

The first class flight attendant was awful to everyone. Very rude; no customer service. She should not be working in first class.

Snacks and included beverages were appreciated. Boarding went smoothly. Plenty of overhead bin space. Seats get very uncomfortable after a couple of hours. After waiting 10 painful minutes for my walker, a very nice Delta guest agent pushed me in a wheelchair to the gate. It was finally delivered to me after another 15 minutes . Our checked bag was on the carousel long b4 I was able to retrieve it. Fortunately it was still there but somewhere along the way the straps we used to secure it were removed and and were not reattached. Wish I had made note of the agents name.

It was fine. 55 minute flight. No snacks or beverage service offered. Boarding went smoothly and my walker was waiting for me on the jet way.

Smaller plane for a longer flight than my first one. Doesn’t make sense.

The cabin temperature was nice and cool. The wifi was not working.

Flight late, the waited for a long time for “personal” to arrive at gate to dock the plane in Rochester. So annoying. This flight was expected, why aren’t personel available for the jet bridge?

As previously noted, this flight was great: departure was timely, the crew was friendly and attentive, and wifi connectivity was seamless. In particular, I appreciated that the flight attendant just told me to stow the laptop right before takeoff/landing, and trusted me to do so (which I did!).

Kayak botched up the booking, i had to call delta and fix. In the process Delta failed to honor my comfort plus seat assignment that i had previously.

Entertainment is ok! Boarding and seat with zone is terrible. I paid for the seats but you didn’t give me what I paid for which is exit isles.

the crew cancel the morning service due to the weather. Then the flight got deverted to Nashville . we were on the ground for over two hours the only gave us water once... no food or any snacks.... the crew should have handled better and offered something to passengers.

Good quick flight on a small but comfortable plane. I'm 6'3 and had plenty of space.

The flight was delayed so we were dead tired, and after that the turbulence was horrible. I was very scared.

Wifi took a while to kick in and we had a maintenance issue that took over 40 mins at the gate in Washington before pulling back

Very good. Because of the delays with my previous flight, I missed my connection, but I was able to book another flight through the United app easily.

Was happy we finally got upgraded in 1st class. The seat getting old. The cushiness need some improvement.

Ineffective communication with United resulted in lost baggage. Their Baggage Tracing counter at MUC was shut down from 11:00-14:15 on my arrival. Undertrained, underinformed staff had me Running all over MUC to find someone to help me to no avail. Staff was rude, unhelpful, and unable to effectively use the systems they did have operational. They refused to contact United in any way or provide any accommodation or other resources while I waited for my luggage. This has destroyed my downstream itinerary. If they had even the slightest visibility I may have been able to reschedule/plan, but again, their staff provided nothing, and did nothing more than their website, which doesn’t even work on a standard phone browser. Miserable failure at all levels that weren’t associated with the operation of the aircraft.

Sat next to a one year old. She crawled all over the place and made me laugh.

The Crew and the food was the worst I ever had in Business Class. First they told us there were no space for carry on. It was plenty of space over our 2 row seats, we had to ask to let us travel with it which was accepted. They were aware that we had to run for the connection due to the previous flight delay. Have us one hour waiting for more customers and not even offer a glass of water. Then started the service and they started to serve other passengers drinks in business and did not offer any drinks until they serve our pre ordered meal and I ask for something to drink. I had to wait until they finished to serve all passengers until Inget something. The crew was the worts I ever had for Business Class in my life.

Not great experience - we were super late boarding due to issues with aircraft. Then when we finally all got onboard and seated and they started taxiing out to the runway they just stopped then turned around and went back to the airport. Apparently the crew “ran out of time” to legally fly us. They mentioned that they were about 2 minutes away from taking off. I understand the rules and safety but kinda wonder why they would have bothered boarding us in the first place? Had to go all the way back and de plane and then wait in a HUGE line to get a hotel (this is somewhere around 2:30am) finally got to hotel by Uber (no shuttle after 20min so gave up) and they ended up putting us all back on the same aircraft at 10am next morning so got about 2.5 hours sleep. They did give us. $250 credit, but it was a São Paulo Brazil flight out of Dulles. The flight and everything was fine.

Starlink wifi on the Embraer E175 is an excellent experience. I was able to connect and work from IAD all the way to approach into BTV.

Departed late. Flight crew some of the most professional I have ever experienced. First time we’ve flown this airline

No difference between business class and normal same seat everything same, waste of money

They allowed me to book the flight, which took quite an effort to find the best option for us, and then 2 months later, cancelled it because they didn't think 90 minutes was enough time to get between connections. Why let me book the flight in the first place? I am somewhat disappointed in Kayak and will be choosing other options in the future

Absolutely unacceptable level of service for a Business class: lousy drink and food options, disgusting food (inedible meat, watery rice, etc...), pathetic level of attentiveness from staff, Business class restrooms were not accessible for long periods because blocked of by staff...overall extremely disappointing, will NEVER fly Business on TAP again.

Should really consider a better, smother boarding. Stood in tunnel for 20 plus minutes. Should start from back passengers of plane. Not front.

The plane was small and one felt the turbulence much more. The lines to get through immigration were insanely long.

First time flying Business with Tap, I think it was a very good experience. It beats many domestic US carriers, the food options were really great, authentic Portuguese food, wines & deserts. Next time will do the free 24-48 hour stopover in Lisbon or Porto for sure.

We upgraded to business class. Nice seat with lots of room but otherwise not impressive.

Delayed departure Madrid to Lisboa and my luggage no arrived

this flight was awful from pre-boarding to on the plane. There needs to be more coordination between TAP and My Way. We were in first class and I am handicapped. BY the time we got on the plane there was no place for our baggage and the crew did not handle the situation well. They gave us an argument and said that we'd have to have it checked. Then, after I complained they moved some people's bags to put our small carry ons several seats back of our seats which were in Row 4.

Awful. They didn't even show concern that her connecting flight( Dallas to Mardrid) was gone/missing. I don't understand how that is even possible. Rudest answer from one of the crew was that American Airlines sold the tickets to somebody else. My daughter was not in the list.

The flight was canceled on a Thursday last minute. I lost thousands of dollars in hotels and car rental

Excellent lie flat seat for premium economy! Great staff. Bad food . Not so great entertainment. My bag didn’t make it either.

Really like the idea experience on this airline I will use again

Plane delayed due to weather. Plane boarded, then told to unboard due to a maintenance issue.

the seats were so cramped you could barely move. it was difficult to eat when passengers would recline their seats. the seats were so flimsy and unstable that whenever someone got in and out of their seat, it bounced like a spring back in your face. the movies were nice. the food was terrible. even though the conditions were terrible, they tried to pressure passengers to relocate their seats to accommodate adults who were related and wanted to sit next to each other, even after the passengers expressed that they did not want to move for that purpose. on the connecting flight, the “service” consisted of items for purchase. even though the flight was only 45 minutes, once again passengers (including me) were pressured to relocate for people to sit next to each other. they couldn’t be apart for 45 minutes? this was much less compelling than being apart for an 8 hour flight.

Everything went smoothly, and we even arrived 40min earlier than scheduled, on an Orland-Madrid route.

The staff was very nice and helpful. Some of the best crew I have met.

Suddenly, I don't find my flight back on the app Help Ticket 0757345716866 Hoeflich Flight back Sunday ib5333 Ib2629 Ib4268

Was all good.l including a sofdrink. AA improved significantly. There was no entertainment.

Lufthansa cancelled our flight from Los Angeles to Naples Italy on March 10 for scheduled flight on March 12 Very stressful experience trying to arrange alternatives. Will never fly again with Lufthansa

Everything could have been better. What needed to be wrong with United went wrong

The staff was bit rude when I asked for an extra drink after one beer, asked for one wine glass.

Very good, i got two seats for myself, and was comfortable with the blanket i got

I hated the FRA Airport. Confusing signage, including the path to Immigration and Security It seems that the airport grew haphazardly over the years. I have been through multiple WW Hubs with much better experiences.

Economy Priority seats are extremely uncomfortable. There is no way to escape the boxed in feeling, particularely because the distance between to rows are too short, the hard edge of the front row is keeping legs confined. There is no elevated place to put your feet. I am of average, European size.

Terrible. Both flights were significantly delayed, no luggage, made me check my small bag when many, many others had much larger carry-ons, not even a bottle of water . . . I will not fly Discover Airlines again.

I was deceived on the Kayak site expecting a ticket, but instead finding a "standby" reservation. When I tried to change the ticket, I paid almost twice the price of the original ticket. Then, the airline refused to give me the reserved seat I had chosen and paid for. I think I deserve a refund for this leg of my trip because I was doubly charged and did not receive what I had paid for. I put in a complaint with Lufthansa because the ticket was sold originally sold as a flight they listed. Someone here needs to take responsibility.

Excellent service; they helped me reschedule so I can fly in an earlier flight

I had a good comfortable seat. There was nearly an hour delay. There was an accident with the champagne, but I was well compensated. These things happen sometimes.

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

Information on your arrival and departure airports