IAD - OPO

$241 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 9/22. 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.
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Everything you should know

Cheapest round-trip
$836
Typical prices: $732-$584
TAP AIR PORTUGAL
Wed 9/30Sun 10/4
IAD - OPO • 1 stop
Cheapest one-way
$241
Typical prices: $378-$594
SWISS
Tue 9/22
IAD - OPO • 1 stop
Top airlines
Cheapest • from $871 (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 • 9h 47m (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 32% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 28% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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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

Wed, Sep 30 - Sun, Oct 4
TAP AIR PORTUGAL Logo
10:35 pm - 11:10 pm
IAD
-
OPO
19h 35m
1 stop
TAP AIR PORTUGAL Logo
10:00 am - 8:35 pm
OPO
-
IAD
15h 35m
1 stop
$836TAP AIR PORTUGAL
Mon, Nov 16 - Thu, Nov 19
Scandinavian Airlines Logo
8:30 pm - 11:05 am
IAD
-
OPO
33h 35m
1 stop
Scandinavian Airlines Logo
5:50 pm - 7:10 pm
OPO
-
IAD
30h 20m
2 stops
$841Scandinavian Airlines
Wed, Sep 30 - Thu, Oct 8
Multiple Airlines Logo
10:20 pm - 6:50 am
IAD
-
OPO
27h 30m
3 stops
Multiple Airlines Logo
7:00 am - 3:45 pm
OPO
-
IAD
37h 45m
3 stops
$864Multiple Airlines
Thu, Oct 8 - Tue, Oct 13
Multiple Airlines Logo
8:30 pm - 10:40 pm
IAD
-
OPO
21h 10m
3 stops
Multiple Airlines Logo
2:00 pm - 7:00 pm
OPO
-
IAD
34h 00m
2 stops
$865Multiple Airlines
Thu, Aug 27 - Sun, Sep 20
TAP AIR PORTUGAL Logo
10:35 pm - 8:25 pm
IAD
-
OPO
16h 50m
1 stop
TAP AIR PORTUGAL Logo
6:00 am - 3:10 pm
OPO
-
IAD
14h 10m
1 stop
$870TAP AIR PORTUGAL
Sun, Jul 26 - Fri, Aug 21
Delta Logo
6:15 pm - 3:30 pm
IAD
-
OPO
16h 15m
1 stop
Delta Logo
5:55 am - 6:33 pm
OPO
-
IAD
17h 38m
2 stops
$871Delta
Tue, Aug 11 - Tue, Aug 18
Multiple Airlines Logo
9:55 am - 7:00 am
IAD
-
OPO
16h 05m
2 stops
Multiple Airlines Logo
2:55 pm - 1:30 pm
OPO
-
IAD
27h 35m
1 stop
$873Multiple Airlines
Wed, Sep 30 - Sun, Oct 4
Delta Logo
4:00 pm - 3:25 pm
IAD
-
OPO
18h 25m
2 stops
Delta Logo
12:25 pm - 7:16 pm
OPO
-
IAD
11h 51m
1 stop
$875Delta
Tue, Jun 2 - Tue, Jun 16
Multiple Airlines Logo
8:18 am - 11:10 pm
IAD
-
OPO
33h 52m
3 stops
Multiple Airlines Logo
10:25 pm - 8:29 pm
OPO
-
IAD
27h 04m
3 stops
$876Multiple Airlines
Mon, Jun 15 - Mon, Jun 22
Multiple Airlines Logo
11:30 am - 6:45 am
IAD
-
OPO
14h 15m
2 stops
Multiple Airlines Logo
1:30 pm - 3:01 pm
OPO
-
IAD
30h 31m
2 stops
$877Multiple 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 September.

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 $564 (return) on average. On the other hand, the most expensive months are May and June, where the average cost of round-trip tickets is $1,210 and $943 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 32% 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$241
Best time to beat the crowds with an average 22% drop in price.
Most popular time to fly and prices are also 4% 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 $241 for a one-way ticket and $871 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 $1,048 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 $883 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 8451 reviews
7.8Comfort
7.2Food
7.8Entertainment
8.5Crew
8.1Boarding
Airline reviews

I continue to be satisfied with Delta’s excellent service out of LGA. The digit id works well and gets me through security in no time. Whenever possible, I choose Delta.

10.0 Excellentangela, May 2026
LGA - PBI
Read more Delta reviews

I continue to be satisfied with Delta’s excellent service out of LGA. The digit id works well and gets me through security in no time. Whenever possible, I choose Delta.

Was revoked with Jet Blue due to delay from Kenya Air

The Boarding process was great. Particularly since my wife and I require assistance. The flight attendants were amazing. We travel frequently; they honestly were a cut above. 😀

Enjoyed it very much. Especially liked the free WiFi that Delta offers.

Smooth flight. Left on time, and got in 15 minutes early. Onboard video was great

For some reason, TSA Atlanta didn’t have my bag on the flight on time and they don’t have to provide Delta a reason for that.

WiFi didn’t work on two of four planes. Flight attendants were not overly friendly or welcoming. Planes were extremely slow to board and deplane.

Delta does a great job with entertainment and free wifi. I can still be in touch with my colleagues while in the air.

Aside from a completely packed plane, I really have no complaints.

Bus to plane was delayed for no apparent reason and our luggage was still on the belt when they shut it off. Took about 20 minutes to turn it back on to get our luggage.

Our flight was canceled same day and we were never informed. Had to pay more and worse seating on another airline.

Did not like that we couldn't complete check in on-line without providing pictures of our passports. Worry about identity theft. We had no delays and boarding was handled In an efficient manner.

Excellent! I got to Munich and was transferred to my Lufthansa flight quickly, in 15 to 20 minutes, so I did not miss my flight. However, I had checked my overhead bag at the boarding gate in Tampa. That got to Tunis the next day. That is to be expected.

WiFi didn’t exist , seats were super cramped, lights stayed on near my seat for a long time while others were dimmed, the food/trash/drink cart hit my shoulder at least a couple of times while moving, food options were down to just one option by the time it got to my row, the utensils were garbage (knife bent at a couple of places by the time I was done eating) the spoon was very flimsy plastic

Vegetarian selection could be better. Bread was too hard to chew.

Crew was friendly and competent. Food, wine, and entertainment were excellent except the raw tuna on the flight to Split. Recommend against serving that - at least as the only option. Many medical conditions do not allow people to eat raw fish.

United didn’t even try to hold the flight for me. They knew I had a tight connection and when I arrived at the gate less than 10 mins after final boarding the flight had already gone. The gate agent wasn’t even notified that I was on my way. She was told I wasn’t at the airport

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

The passport control process in Lisbon ranks as a 1 on a 1 to 5 scale. Terrible. In line 2 hours and still missed our first flight. Next day, 1.5 hours but we made the flight. The Business Class food was poor. Unidentifiable. Not tasty at all. Unacceptable in BC. Attendants were adequate. Flight left late and arrived late. After this trip, we will not be flying TAP nor will we be connecting through Lisbon.

Flight attendants in business class were rather indifferent While in second leg operated by Portugalia TAP subsidiary were outstanfy

Great service overall. One of the best international flight experiences Ive had.

The chicken was so dry it was impossible to eat. No substitute was offered. The port to charge my phone was broken and all I got was a shrug from the crew. The entertainment system was glitchy and subtitles didn’t load. Crew seemed fully uninterested and unfriendly.

The flight crew were absolute rock stars. When they came to the gate they looked like royalty, so chic. They also were extremely kind. Food was good and I loved the lack of plastic waste. The flight was lovely and smooth.

We were unable to check in due to technical problems on TAP’s end. The flight was delayed forty minutes with no reason given. We received timely notice of the flight delay. We were also notified of a gate change. The new gate was at a different terminal. When we got to the new terminal, we learned that we had to go back to the old terminal first to check in. This information should have been included along with the gate change notification. Also unexplained, the steward skipped us when offering breakfast.

They left our luggage uncovered on tarmac in pouring rain during an hour delay of departure! At our final destination, we found ALL OF OUR CLOTHES/SHOES soaked all the way through!! Our 1st connection plane was a great business class accommodation but only 50 minutes long. Our 2nd connection from Lisbon (another delay with luggage uncovered on tarmac) had only the extra legroom and mediocre food in business class - no entertainment and no extra comfort seating. Will not use TAP Air Portugal again!

The food left a lot to be desired. The crew was great

Horrible experience at tbe check in ladie she was very racist ,she doesn't speak portuguese too and forced me to check in my carrion bag and I saw everyone with carrion bag inside anda lot of space ,she was rude unprofessional

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

In general, I've had excellent experiences with Iberia flights and will continue to use them. In this last flight there were two things that didn't go right. I didn't get the kosher meal I had pre-requested when I had checked in on-line. Things worked out OK as we ended up eating the fish and vegetarian choices, which were really good. The other issue was that some movies for me and my wife started fine but after 8-12 minutes the content just switched to something else. The flight attendant reset our entertainment systems, but the problem persisted. We ended up choosing other movies/TV shows that did work fine.

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

Good food, overall very comfy. The flight was full so obviously not optimal, but it is what it is.

Perfect airline, super friendly, great service, tasty food. Would fly again.

Parents with permanently crying baby on board. Neither parents nor crew did anything to calm the baby. The food was extremely disappointing. Seafood stew was very, very small! Not even appetizer size! Seat had a gap in the back. Had to use a pillow to fill it.

Food choices limited & not enticing Seats quite uncomfortable & difficult to control

Definitely get premium economy on a flight this long if you can. Your legs and while body will thank you.

Flight was delayed by several hours and then cancelled due to weather. But Staff was very helpful getting me on a different flight. United should offer food coupons and tooth brush and paste for stranded passengers

I upgraded to the business class cabin. It was the poorest business class I have ever experienced. No access to any business lounge in Tampa airport. Seats are not comfortable. I had a window seat and had to step/crawl over the next seat. Food was mediocre and service below average for business class. Bathroom location was ridiculous. No place to wait. I cannot believe I paid this kind of money and will never fly Lufthansa Discover again. They really should reimburse me somehow.

Boarding was disorganized. The door to one to the toilets wouldn’t lock. The plane was shockingly cramped, and clearly used for domestic flights due to the menus for items to sell domestic travelers. United should be ashamed of its small seats, tiny unclean toilets, and money grubbing stance toward services, compared to Lufthansa, Emirates, and most international carriers United is awful.

Was never allowed on and not refunded the full amount of the ticket plus charged a $300 processing fee.

Terrible. Lost our luggage for 4 days. Did not advise passengers there was a strike in Barcelona Airport and had zero personnel on hand at airport to advise passengers on where to go to file claims. We had to fend for ourselves. No assistance at all other than an online claims submission process that we had to find out about on our own.

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

Information on your arrival and departure airports