IAD - OPO

$289 Find Cheap Flights from Washington Dulles Airport to Porto - Compare and Save

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 8/16. 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
$851
Typical prices: $803-$677
Multiple Airlines
Mon 9/21Fri 9/25
IAD - OPO • 2 stops
Cheapest one-way
$289
Typical prices: $458-$558
Multiple Airlines
Sun 8/16
IAD - OPO • 2 stops
Top airlines
Cheapest • from $879 (round-trip)
Best reviews • 7.8 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 $665 (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 2 weeks in advance save around 24% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 35% price drop
Most popular
Good to know
Good to know
+1
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Good to know
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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

Mon, Sep 21 - Fri, Sep 25
Multiple Airlines Logo
8:30 pm - 11:20 pm
IAD
-
OPO
21h 50m
2 stops
Multiple Airlines Logo
6:35 am - 10:15 pm
OPO
-
IAD
20h 40m
2 stops
$851Multiple Airlines
Mon, Sep 21 - Fri, Sep 25
Multiple Airlines Logo
5:00 pm - 9:25 am
IAD
-
OPO
11h 25m
1 stop
Multiple Airlines Logo
10:20 pm - 7:10 pm
OPO
-
IAD
25h 50m
2 stops
$861Multiple Airlines
Mon, Aug 17 - Fri, Aug 21
Multiple Airlines Logo
5:00 pm - 10:50 am
IAD
-
OPO
12h 50m
1 stop
Multiple Airlines Logo
8:25 am - 10:45 am
OPO
-
IAD
31h 20m
2 stops
$868Multiple Airlines
Thu, Sep 3 - Wed, Sep 9
TAP AIR PORTUGAL Logo
10:35 pm - 6:55 pm
IAD
-
OPO
15h 20m
1 stop
TAP AIR PORTUGAL Logo
7:00 am - 3:10 pm
OPO
-
IAD
13h 10m
1 stop
$871TAP AIR PORTUGAL
Sun, Aug 16 - Fri, Aug 21
Multiple Airlines Logo
5:00 pm - 8:00 pm
IAD
-
OPO
22h 00m
1 stop
Multiple Airlines Logo
8:25 am - 10:45 am
OPO
-
IAD
31h 20m
2 stops
$873Multiple Airlines
Fri, Sep 25 - Sat, Oct 3
Multiple Airlines Logo
8:30 pm - 9:25 pm
IAD
-
OPO
19h 55m
2 stops
Multiple Airlines Logo
7:50 pm - 3:10 pm
OPO
-
IAD
24h 20m
2 stops
$876Multiple Airlines
Wed, Oct 7 - Tue, Oct 13
Multiple Airlines Logo
11:20 pm - 12:40 am
IAD
-
OPO
20h 20m
3 stops
Multiple Airlines Logo
10:00 pm - 7:00 pm
OPO
-
IAD
26h 00m
3 stops
$877Multiple Airlines
Wed, Oct 7 - Sun, Oct 11
Multiple Airlines Logo
5:00 pm - 10:10 am
IAD
-
OPO
12h 10m
1 stop
Multiple Airlines Logo
5:55 am - 3:30 pm
OPO
-
IAD
14h 35m
1 stop
$878Multiple Airlines
Sun, Nov 1 - Thu, Nov 5
TAP AIR PORTUGAL Logo
10:30 pm - 3:00 pm
IAD
-
OPO
11h 30m
1 stop
TAP AIR PORTUGAL Logo
8:30 am - 3:15 pm
OPO
-
IAD
11h 45m
1 stop
$879TAP AIR PORTUGAL
Sun, Oct 4 - Mon, Oct 12
Multiple Airlines Logo
5:00 pm - 8:50 am
IAD
-
OPO
10h 50m
1 stop
Multiple Airlines Logo
6:15 am - 7:25 pm
OPO
-
IAD
18h 10m
2 stops
$880Multiple 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 $530 (return) on average. On the other hand, the most expensive months are May and June, where the average cost of round-trip tickets is $1,218 and $1,063 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 2 weeks before departure, which saves you about 24% 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$289
Best time to beat the crowds with an average 25% drop in price.
Most popular time to fly and prices are also 5% 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 5 days, the lowest price for a flight from Washington, D.C. Dulles Intl Airport to Porto was $289 for a one-way ticket and $876 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 7.8, 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.
7.8
DeltaOverall score based on 8414 reviews
7.8Comfort
7.2Food
8.1Boarding
7.8Entertainment
8.5Crew
Airline reviews

Horrible. Faucet in sink not working, wifi not working. Didn’t bring food or snacks

2.0 MediocreMargaret, Jun 2026
MSY - LGA
Read more Delta reviews

Horrible. Faucet in sink not working, wifi not working. Didn’t bring food or snacks

Flight was delayed before take off and at landing. Baggage took 20 minutes. Flight crew would not serve full soft drink and had to ask multiple times before receiving water.

From checking to boarding, it was a seamless experience. The service agents were so helpful. The flight crew was so pleasant.

Gate agent showed up 20 minutes before boarding and was not at all friendly. Had to take this flight due to the one on the day before being cancelled and any later options were already full with long standby lists. Despite having paid for Delta Comfort seats, Delta did not allow me (or anyone) to choose their seat. The agent assigned them for everyone just prior to boarding. Self seat selection was allowed on the original flight. Flight staff was great - very friendly.

Flight attendants were great. Cheerful, upbeat and friendly. Jet, in particular, was fantastic.

I have Precheck. Flew HPN to DEN and return this past weekend. Delta didn't attach my Precheck number to this trip. So it was waiting in general line especially in Denver. Unavailable.

Original flight was delayed, then cancelled and the gate staff did not expedite rebooking. Also, no instructions were given that a ticket number was needed before being called to facilitate rebooking. This could have been much more organized.

Be on time? When not on time a circling for over an hour offer more than 1 bag of chips to the passengers? It was a 7 hour flight by the time we got done.

Five hour delays every hour, I wish it were all at once

Flight delayed four separate times. I’m now one hour hours late to landing.

Like: departed and arrived on time. Unlike: Food options for purchase allways bad, 1 of 2 of the crew members not very friendly at all. Seats and leg room aweful. At this point I am thinking on switching to AA.

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.

There were no delays. I almost lost my connection because of the new EES system

It was a game of hurry up and wait. As advised we arrived at the terminal e hours prior to boarding. We waited about 45 minutes before anyone showed up at the check-in terminal. When someone does arrive she rearranges the line and we think we are going to be checked in. Nope. She leaves and we wait another 15 min. before anyone else shows up. One person got behind her computer and about 15 min later started to check the first person in . Then one more person arrives spends 10-15 behind the desk and then she starts checking in someone. Two more staff arrive and another 10 min or so they are ready to begin checking in people. We have a 11:50 international flight and it is 9:45. And then on of the agents, closes her desk and leaves. And every leg of our flight was delayed; we waited at terminals, we waited to take off, we waited to deplane. After arriving in Porto within 10min of our connection schwduled to take off, we were told to go to the last bus. We waited on the bus (until all the other busses had left) and then we waited another 10 min or so for one of the ground controllers who wanted a ride with us but was busy with a woman who needed the handicap van. He did not help her to the van, but was standing with her and talking with hher. We were rushed through border control and told not to wait for the rest of our party only to get on the plane and then have to wait another 45 min before we were cleared for take off. The waits were not 10 or 20 minutes, they were 35-55 minute waits each time. Miraculously, we made it back only 2 1/2 hours later than we we were originally scheduled. Given the nonchalance and seaming disinterest from many of the staff, I was expecting that we would not get on until much later than that.

The crew was excellent. What I did not enjoy was the food. I have taken many international flights and this was on the low end. Otherwise the trip was fine.

Seats were the most uncomfortable seats i ever experienced on a flight to Europe from Boston. It was a waist of money in buying premium seats for top dollars. I want my money back for what i paid extra for my seats. Awful conditions!

On the seat map for this flight with TAP was shown a business class configuration of 2 rows/8 seats. To my surprise, 4 rows/24 seats being the middle is kept empty, old European type. I chose seat 2F, the the leg room economy dimension. This is not what I paid for. Disappointed!

Boarding felt a little chaotic as everyone was waiting around the gate. Food was great, service was good.

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.

Not bad but they lost 2 of my bags when I got to Florence

Puddle-hopper. Quick-ish flight. Don’t expect to have much/any in-flight entertainment (movies/TV, etc).

Couldn’t get boarding passes online, delayed an hour, and smallest amount of space on board I’ve ever encountered for such a long flight.

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.

We sat in our seats on the tarmac for almost 3 hours due to storms. They would not give us water or a snack. We were to depart at 7.30 pm and it was about 10.30 when we took off. No dinner until much after that. Beef type noodle dish was terrible with about a teaspoon of beef in it. The breakfast sweet waffle with egg and sausage inside was horrible. An English muffin sandwich would have been much better. Food was the worst in all of our years of traveling the world.

Our screen kept turning off ...3 times...had to get crew attention to turn it on again

They messed up my seat so I didn’t get the one I paid for

Put me on standby; flight was late; missed my connecting flight; disaster

Flight attendants were fine, seats a bit hard but I use a cushion for extra support. The only issue was it was a bit too cool and I needed to ask for and received and extra blanket. I survived!!!

Very few things and/or people are excellent. It was very good.

Extremely uncomfortable seats. Experience was like a Frontier Airlines flight. Would not fly it again.

Very, very tight legroom. They must’ve jammed in an additional few rows of seat seating. Denver to Munich was the least legroom I’ve ever had on any flight, let alone a multi hour international journey. I will not take that flight again.

In my first flight with Air Canada we sat in the plane for 4:00pm to 6:30pm. Finally we were asked to get off the plane and we were told the flight was cancelled after 7:00pm There was o clear explanation of what was the problem. I was booked without my permission on a Delta Flight at 7:30pm that was leaving at 8:00pm and I still had to go get my luggage(my final destination was Rome with one stop in Toronto. The luggage claim for Canada was closed so had to return to finally get it on the luggage belt.. Of course I missed the Delta flight and all the next day flights were booked. I also lost what I paid for my stay in Rome because I did nt cancel in time. A complete nightmare.

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

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

Information on your arrival and departure airports