IAD - OPO

$235 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 8/12. 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

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 20% 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.

Flights Deals
Useful Info
Flights 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, Dec 3 - Wed, Dec 10
 Logo
9:55 am - 6:35 pmIAD-OPO
27h 40m2 stops
 Logo
7:20 pm - 4:30 pmOPO-IAD
26h 10m1 stop
Wed, Dec 3 - Wed, Dec 10
 Logo
4:30 pm - 6:35 pmIAD-OPO
21h 05m2 stops
 Logo
6:00 am - 8:29 pmOPO-IAD
19h 29m2 stops
Wed, Dec 3 - Wed, Dec 10
Lufthansa Logo
11:10 pm - 11:45 pmIAD-OPO
19h 35m1 stop
Lufthansa Logo
6:00 am - 3:50 pmOPO-IAD
14h 50m1 stop
$492Lufthansa
Find Deal
Sun, Aug 17 - Tue, Sep 2
TAP AIR PORTUGAL Logo
10:20 pm - 5:00 pmIAD-OPO
13h 40m1 stop
TAP AIR PORTUGAL Logo
6:00 pm - 3:20 pmOPO-IAD
26h 20m1 stop
$499TAP AIR PORTUGAL
Find Deal
Tue, Sep 16 - Mon, Sep 22
TAP AIR PORTUGAL Logo
5:00 pm - 8:00 amIAD-OPO
10h 00m1 stop
TAP AIR PORTUGAL Logo
8:50 am - 3:20 pmOPO-IAD
11h 30m1 stop
$504TAP AIR PORTUGAL
Find Deal
Sun, Dec 7 - Thu, Dec 11
Iberia Logo
6:00 pm - 11:45 amIAD-OPO
12h 45m1 stop
Iberia Logo
8:20 am - 4:30 pmOPO-IAD
13h 10m1 stop
$534Iberia
Find Deal
Wed, Nov 12 - Sun, Nov 16
Lufthansa Logo
11:10 pm - 11:45 pmIAD-OPO
19h 35m1 stop
Lufthansa Logo
6:00 am - 3:50 pmOPO-IAD
14h 50m1 stop
$548Lufthansa
Find Deal
Wed, Nov 12 - Sun, Nov 16
United Airlines Logo
9:55 am - 3:25 pmIAD-OPO
24h 30m2 stops
United Airlines Logo
6:00 am - 11:59 pmOPO-IAD
22h 59m2 stops
$562United Airlines
Find Deal
Sun, Dec 7 - Thu, Dec 11
Iberia Logo
6:00 pm - 4:00 pmIAD-OPO
17h 00m1 stop
Iberia Logo
12:25 pm - 3:35 pmOPO-IAD
32h 10m2 stops
$565Iberia
Find Deal
Sat, Nov 29 - Sat, Dec 6
United Airlines Logo
5:50 pm - 11:40 amIAD-OPO
36h 50m2 stops
United Airlines Logo
12:40 pm - 3:50 pmOPO-IAD
32h 10m1 stop
$572United Airlines
Find Deal
Useful Info

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 $883 respectively.

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

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

To get a below average price on the flight from Washington, D.C. Dulles Intl Airport to Porto, you should book around 3 weeks before departure. For the absolute cheapest price, our data suggests you should book 17 weeks before departure.

Good to know

Low seasonFebruary
High seasonAugust
Cheapest flight$235
Best time to beat the crowds with an average 25% drop in price.
Most popular time to fly with an average 2% 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 $235 for a one-way ticket and $472 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, 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, United Airlines or TAP AIR PORTUGAL?

    The two airlines most popular with KAYAK users for flights from Washington, D.C. to Porto are United Airlines and TAP AIR PORTUGAL. With an average price for the route of $804 and an overall rating of 7.4, United Airlines is the most popular choice. TAP AIR PORTUGAL is also a great choice for the route, with an average price of $742 and an overall rating of 7.1.

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

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

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

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

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

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

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

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

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

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

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

 
See real verified KAYAK customer reviews for airlines flying from Washington, D.C. to Porto. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Dulles Intl to Porto? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
DeltaOverall score based on 7969 reviews
7.9Comfort
8.2Boarding
7.9Entertainment
8.5Crew
7.3Food
Airline reviews

Crew was excellent. Comfort seats not as nice as other kinds of planes.

10.0 ExcellentMary, Jun 2025SAN - ATL
Read more Delta reviews

Crew was excellent. Comfort seats not as nice as other kinds of planes.

Not a "Delta" issue, but a JFK issue: We booked a connecting flight with 3 1/2 hours between to clearn immigration and customs. Our inbound flight (BCN to JFK) was on the taxiway 45 minutes which ate into our layover time. Immigtration was insanely quick with the CBP MPC app; however, clearing TSA (again, after we were ALREADY cleared in Spain on the inbound international flight) took over 95 minutes. This left us with 10 minutes before boarding the connecting flight (JFK to SAN) to walk to the far end of Terminal 4 and try to find food. We didn't find any food that could promise to serve us in under 10 minutes so we boarded the Delta flight after coming off a plance and an 8-hour flight knowing that we wouldn't be served any food on the next 5 1/2 hour flight. I feel like Delta needs to put pressure on the JFK TSA to open more screening stations (by our count, we saw only 5 scanners open and a line of - as we said - over 90 minutes. The insult is that we WERE ALREADY SCREENED through TSA, but as you come off one flight into the USA, you have to go through the whole process again. It seems like if you have a connecting flight, there should be a way to pass through immigration and customs without needing to return through TSA.

It was a great flight and the stewards and stewardess were all kind and accommodating!! The seats were comfortable and entertainment screen excellent!

There are 4 flights in consecutive gates with about the same departure time. Two flights were boarding at the same time. One was delayed or boarding would be happening at the same time. I am not sure what Delta and LAX need to do to have a better layout at the end of Terminal 2

Flight was an hour late, who knows why. It was OK, nothing outstanding.

Only not having an assigned seat was an issue. Rest was great

There was a security issue at the airport and we were unable to land. We circled endlessly and then landed at another airfield for fuel. We then circled the airport again, almost landed but didn’t fully touch down before circling again. I am thankful to the crew for keeping us safe- the issue was the airline and staff at the airport getting us seats on our connecting flights. That part was hours of searching for someone and getting in double my steps.

Boarding was organised and relaxed. Crew were fantastic! Seats were lacking padding causing butt pain and stiffness.

I like for how they process during check in. It was very smoothly.

The flight was scheduled for 2:30 PM. Early in the morning we got a text message saying the flight was delayed and rescheduled for 3:00 PM. We got to the airport with that in mind. Then we got a message during check-in at the flight was rescheduled again for 2:30 PM. We almost missed our flight. In fact, our bags Were told that they would not make it. At the end, everything worked out. But it is very stressful.

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

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

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

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

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

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

You should not have to pay for WiFi in business class

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

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

I 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

I love flying with United. Unfortunately, I flew on an older plane with minimal upgraded technology (no Bluetooth functionality or handy charging ports). Otherwise, the flight was great and even arrived early.

They changed my seats after I checked in and I was stressed from the time I saw that information until just before boarding, when the gate attendant fixed it, but it shouldn't have happened. And if it couldn't be prevented, then the people on the phone I spoke with should have done something to help, which they did not, nor did they offer me compensation, just meaningless apologies.

online check in was not available so i had to get to airport extra early. The flight was delayed and my luggage was lost. I had an argument with the person behind me who wanted to keep her bag on the floor and not allow my seat to recline on a 9hr plus flight. So overall, lots and lots of areas for improvement.

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

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

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

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

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

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

The flight was heavily booked so boarding was a lengthy process. The FA’s were rather abrupt during this process but became more gracious as the flight went on. Breakfast (puffed pastry and chewy sausage) was pretty horrible but there was fruit and yogurt which they didn’t mess up. Overall it was fine.

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

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

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

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

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

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

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

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.

It was a wonderful experience with great food, great staff, and no difficulties boarding!

Paid for my seat 4 months ago. Did not pay the extra for specific seat assignment ( never have and never was a problem). Could not electronically check in (found out it was due to overbooking and that unassigned seats get bumped first - never happened to me before). Luckily, did make the flight. Very stressful - would have been extremely disruptive for my travel plans. UK Visa - never notified by Kayak or BA that a visa was required. Had to spend 15 minutes to download and complete app at the flight counter and pay $25, and was told they would let me know in 3 days if I would get it (flight landing in 10 hours from when I completed app). Luckily, visa was approved before landing. Unnecessary stress created here. Food - main meal, curry chicken barely palatable with unrecognizable vegetable. Desert cup, cheesecake, also barely palatable. Salad cup was good. Small water offered only 3 times (before main meal, at main meal, at morning snack) - not nearly enough for long flight.

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

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

Information on your arrival and departure airports

Not what you’re looking for? Find thousands of other hotels, flights, car rentals and package deals with KAYAK.