IAD - OPO

$259 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 8/3. 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

Thu, Sep 4 - Mon, Sep 8
 Logo
10:20 pm - 10:05 pmIAD-OPO
18h 45m2 stops
 Logo
9:20 am - 8:50 pmOPO-IAD
16h 30m2 stops
Mon, Oct 6 - Mon, Oct 20
TAP AIR PORTUGAL Logo
5:45 pm - 8:25 pmIAD-OPO
21h 40m1 stop
TAP AIR PORTUGAL Logo
7:00 am - 8:50 pmOPO-IAD
18h 50m1 stop
$501TAP AIR PORTUGAL
Find Deal
Wed, Nov 19 - Wed, Nov 26
 Logo
9:55 am - 11:15 amIAD-OPO
20h 20m2 stops
 Logo
12:10 pm - 4:30 pmOPO-IAD
33h 20m1 stop
Thu, Oct 23 - Tue, Nov 4
Iberia Logo
4:35 pm - 7:35 amIAD-OPO
10h 00m1 stop
Iberia Logo
8:20 am - 4:30 pmOPO-IAD
13h 10m1 stop
$538Iberia
Find Deal
Mon, Dec 1 - Sun, Dec 7
Iberia Logo
6:15 pm - 7:40 amIAD-OPO
32h 25m2 stops
Iberia Logo
8:20 am - 4:30 pmOPO-IAD
13h 10m1 stop
$547Iberia
Find Deal
Sun, Oct 26 - Sun, Nov 2
United Airlines Logo
6:30 am - 3:15 pmIAD-OPO
28h 45m2 stops
United Airlines Logo
5:00 am - 9:20 pmOPO-IAD
44h 20m2 stops
$561United Airlines
Find Deal
Wed, Nov 12 - Sun, Nov 16
United Airlines Logo
8:30 am - 3:25 pmIAD-OPO
25h 55m2 stops
United Airlines Logo
6:00 am - 11:59 pmOPO-IAD
22h 59m2 stops
$565United Airlines
Find Deal
Sun, Jul 6 - Tue, Jul 22
Delta Logo
9:20 pm - 9:35 pmIAD-OPO
19h 15m1 stop
Delta Logo
6:35 am - 4:20 pmOPO-IAD
14h 45m1 stop
$686Delta
Find Deal
Tue, Jul 15 - Tue, Jul 22
KLM Logo
6:30 pm - 3:30 pmIAD-OPO
16h 00m1 stop
KLM Logo
6:35 am - 4:20 pmOPO-IAD
14h 45m1 stop
$687KLM
Find Deal
Mon, Jul 28 - Wed, Aug 20
Delta Logo
9:20 pm - 3:30 pmIAD-OPO
13h 10m1 stop
Delta Logo
6:15 am - 3:35 pmOPO-IAD
14h 20m1 stop
$690Delta
Find Deal
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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 $953 and $884 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 17 weeks before departure.

Good to know

Low seasonFebruary
High seasonAugust
Cheapest flight$259
Best time to beat the crowds with an average 25% drop in price.
Most popular time to fly with an average 1% 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 $259 for a one-way ticket and $500 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, SkyTeam, and oneworld 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 $820 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 $662 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.

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 7950 reviews
7.3Food
8.2Boarding
8.5Crew
7.9Entertainment
7.9Comfort
Airline reviews

Great service. Flight was delayed while we sat on the runway for a couple of hours. Weather related. Staff made is very bearable. The steward servicing the first class cabin was exceptional. Thank you! 💗

10.0 ExcellentHartaj, Jun 2025EWR - RDU
Read more Delta reviews

Great service. Flight was delayed while we sat on the runway for a couple of hours. Weather related. Staff made is very bearable. The steward servicing the first class cabin was exceptional. Thank you! 💗

5 hours of delay that could've been much shorter if Delta had taken the 1 hour delay they imposed on the flight before boarding to run any of the plane checks required for flight to find the hydraulic issue that required nearly 3 hours to fix. $24 of meal credit buys a sandwich and a soft drink. Poor communication within the terminal about what gate we'd be re-boarding from and when we'd be re-boarding.

Great flight! Only complaint I had was that I didn’t get breakfast that morning because I don’t eat eggs for breakfast.. I ate an energy bar I bought in the airport which I had never done before. Otherwise, another great Delta flight!

Amazing flight! I have never noticed the uniforms of the attendants before in twenty years of flying except today when one female had the most amazing dress on. It was beautifully designed and showed she was in charge. I never dreamed I would google who designed Delta uniforms . The ultimate compliment is when another woman admires your outfit. . I hope your designer puts it on the market

It would be nice if was given wires ear buds. Overall was a good experience was able to sleep on the plane

My flight was 6 pm 6/6. Every hour they delayed it again - air condition issues then no pilot then the crew had worked too many hours and cancelled the flight at 11 pm. Sent customers to NJ a 45 minutes uber ride to a hotel. Had to be back by 5 am for a 7 am flight and again no pilot etc with another three hours of delays.

The entertainment and wifi mostly didn't work on this flight.

Terrible entertainment system - kept freezing and audio kept cutting out. Snacks were mediocre at best for a 5 hour flight.

The check in and bag drop off for Sky Priority members is slow. The Clear security was also slow - a TSA issue.

I am still upset that my bag was lost on a recent trip to Rome ; we were inconvenienced and out €150 Euros ; delta has refused to reimburse us

Klm start boarding while somw air issue in the plan

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 flew premium economy and this was a good option. Although the seats didn’t recline much, I was able to get some sleep with my head propped against the window. The food was good and the entertainment was wonderful The staff were very attentive and professional

it was so bad. I tried to board my flight from vancouver to saskatoon. And to my surprise they did not board me cause the flight was changed and no email was send to me. and on my boarding pass which i got from seattle says different flight. I did not knew anyone from Vancouver, air canada crew was rude, i asked for today flight but they were rude and i had early morning dental appointment in saskatoon. I was so much in pain and my whole day is wasted today. and i suffered alot. They did provide me hotel but they did not provide me any food. I am really really disappointed first time had so bad experience with air canada. I may think twice to book it again. If i can get any reply or any composition that would be great. Thanks

It was fine, definitely older planes with no charging or anything. There’s no entertainment set up on board, but it is nice that they allow you to access the in flight entertainment from your phone without having to pay for the Wi-Fi and they do offer free texting.

Terrible. Out flight was delayed for 21 (twenty one) hours. United is a joke.

Boarding was mayhem. Late boarding by 15 minutes because of lack of staff (missing 1 flight attendant. We had to wait for an arrival of another plane before we could board). Flight was a little rough, but cannot blame on airlines.

Impressed with the service despite turbulence because of the weather. Both flights arrived before their scheduled times.

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.

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

Checked bG chstgr was extremely high. Over $120. It was s bsit and switch knowing an international passenger would have t9 check a bag.

First, communication was terrible. The gate on our ticket was not what was reflected on the airport screens and TAP personnel were not present at either gate to answer questions. The flight was delayed and there was no announcement. Also, there was an equipment swap to a smaller airframe which affected our level of comfort. The root of all these issues was as a lack of communication. With air travel in foreign countries already being a stressful affair, lack of communication needlessly raises the level of difficulty.

Checkin was very slow, we had checked in online and hoping we could do a bag drop at the airport. However everyone with checked bags had to queue up and it took over 40mins. Our advice arrive extra early or you will be rushing to the gate.

On time, politeness, food okay but entertneiment mediocre with only old movie and the so called new we’re 2 or 3…

Do you have a bad service And And treat customers terrible

Awful. I told them to cancel my return flight and they didn’t then charged me +$800 days before the flight for a biz class upgrade bid. When I called to confirm cancellation and get refund on buz class upgrade they said I had to go thru orbitz and it was too late. Scammers. Beware.

Little leg room in business. I am tall and could use more.

Was a cheap flight and it got me to Portugal on time. For economy there was ample leg room and the flight attendants were pleasant and helpful.

Flight was packed. This was a very uncomfortable experience. Boarding process could be explained better. Despite recommending a window seat when travelling with a pet in the cabin, the seat in front of me had less space than the center and aisle seats. For Premium Economy, the seats were crammed with minimal legroom. I hate to think what Regular Economy was like. The cabin crew missed me at first when handing out meals. When my meal eventually came, there were no utensils. I'd originally booked to fly Business Class; those seats didn't look that great either.

From boarding, to attention in flight, I couldn’t fault it.

Not having to check carry on bags when plane wasn’t full. (The told us it was)

I was in business class for the 8 hour flight where: 1. The WiFi did not work 2. The entertainment system did not work 3. We were told there were no hot drinks for the entire flight

I had an issue with the name on my ticket vs my passport name. I was very upset that the Iberia ticket clerk had no authorization to help me and I was left to fix it. It took 19 calls of persons promising to accomplish and not doing anything before I reached someone who helped me in 10 minutes. Two of them even hung up on me. I missed my original flight because of this. Terrible customer service.

The flight was delayed twice. When the crew explained about the debris causing flat tires, I was glad they took the time to change all four.

My carry-on bag was taken from me when I boarded. It was checked through to London at no charge. It took a big of shuffling, but I was glad not to need to mind it until baggage claim.

Flight boarded three hours late for no reason other than someone made a huge error in crew scheduling. We missed our connecting flight in Madrid and got zero help from American or Iberian airlines on rebooking. We had to pay for a car to take us to the Madrid train station and pay for train tickets to Santiago. We never used our booked flight to Santiago. American claims I can submit the expenses but they are not obligated to cover them. Very frustrating.

Flight delayed Service could be better Iberia staff are not really friendly

They cancelled the flight)(they said bad weather but many other flights took off) and made us wait 5 hours in line to figure out what to do. We ended up making a new flight the next day on another airlines...I hope they honor giving us our money back

The seats were way too crowded. Just because I do not have the luxury of a suite, does not mean that I want to fly from Austin to London scrunched between two people and the seat in front of me in my face. Ridiculous. I should have flown with Turkish Airlines...

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