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$235+ Cheap flights from Dulles Intl (IAD) to Porto (OPO)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 9/1. Fares are subject to change and may not be available on all flights or dates of travel.
IAD — OPO
Aug 22 — Aug 291
Sat 8/22
Sat 8/29
1 adult, Economy
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Cheap flight deals from Dulles Intl to Porto

Cheapest flights from Dulles Intl to Porto
Explore the most affordable flight options available from Dulles Intl to Porto. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 23, 2026.

This oojo deal was found by Cheapflights users on 7/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/2510:35 pm
IAD
-
OPO
1 stop16h 50m
TAP AIR PORTUGAL
Sun 8/3010:30 pm
OPO
-
IAD
1 stop21h 40m
TAP AIR PORTUGAL
Deal found 7/20$729
This oojo deal was found by Cheapflights users on 7/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/1710:35 pm
IAD
-
OPO
1 stop15h 25m
TAP AIR PORTUGAL
Sat 8/299:00 am
OPO
-
IAD
1 stop11h 10m
TAP AIR PORTUGAL
Deal found 7/22$731
This Mytrip deal was found by Cheapflights users on 7/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/68:30 pm
IAD
-
OPO
2 stops19h 25m
Multiple Airlines
Tue 10/132:00 pm
OPO
-
IAD
2 stops34h 00m
Multiple Airlines
Deal found 7/21$735
This Kiwi.com deal was found by Cheapflights users on 7/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/2410:55 pm
IAD
-
OPO
1 stop20h 00m
Multiple Airlines
Mon 1/118:20 am
OPO
-
IAD
1 stop13h 00m
Multiple Airlines
Deal found 7/20$737
This Air Canada deal was found by Cheapflights users on 7/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/205:15 pm
IAD
-
OPO
2 stops32h 45m
Air Canada
Wed 11/116:00 am
OPO
-
IAD
2 stops19h 10m
Air Canada
Deal found 7/22$742
This Kiwi.com deal was found by Cheapflights users on 7/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/145:15 pm
IAD
-
OPO
2 stops15h 25m
Multiple Airlines
Mon 10/198:20 am
OPO
-
IAD
1 stop12h 10m
Multiple Airlines
Deal found 7/22$743
This Kiwi.com deal was found by Cheapflights users on 7/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/198:30 pm
IAD
-
OPO
2 stops14h 30m
Multiple Airlines
Thu 9/2412:25 pm
OPO
-
IAD
1 stop11h 30m
Multiple Airlines
Deal found 7/21$747
This Delta deal was found by Cheapflights users on 7/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2712:30 pm
IAD
-
OPO
2 stops18h 05m
Delta
Tue 11/105:00 am
OPO
-
IAD
2 stops16h 30m
Delta
Deal found 7/21$751
This Mytrip deal was found by Cheapflights users on 7/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/108:30 pm
IAD
-
OPO
2 stops17h 55m
Multiple Airlines
Tue 10/132:00 pm
OPO
-
IAD
2 stops34h 00m
Multiple Airlines
Deal found 7/22$753
This Delta deal was found by Cheapflights users on 7/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/76:00 am
IAD
-
OPO
2 stops46h 05m
Delta
Fri 11/135:00 am
OPO
-
IAD
2 stops23h 02m
Delta
Deal found 7/20$758
This oojo deal was found by Cheapflights users on 7/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/1810:50 pm
IAD
-
OPO
1 stop10h 40m
TAP AIR PORTUGAL
Thu 10/17:00 am
OPO
-
IAD
1 stop18h 35m
TAP AIR PORTUGAL
Deal found 7/22$759

Find flight deals from Dulles Intl to Porto

Discover tips and strategies to find the most affordable flight options for your journey from Dulles Intl (IAD) to Porto (OPO). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated July 23, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$729
(oojo)

One-way from

$235
(Kiwi.com)

Popular in

May

Cheapest in

October

Average price

$994
Provider with most accurate pricing for Washington, D.C. Dulles Intl-Porto flight deals.
Search Deals
Provider most trusted by Cheapflights users for Washington, D.C. Dulles Intl-Porto flights.
Search Deals
From Washington, D.C. Dulles Intl to Porto
Search Deals
One-way flight from Washington, D.C. Dulles Intl to Porto
Search Deals
Highest demand for flights based on searches. 17% potential increase in price ($172 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($38 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in July 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Dulles Intl to Porto that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated July 23, 2026.
Use the filters below to find and compare flights from Washington, D.C. Dulles Intl Airport to Porto that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

Washington, D.C.Porto

IAD - OPO

IADOPO

Washington, D.C. Dulles Intl

Wed 10/21

8:30 am-7:00 am

2 stops17h 30m

Porto

Fri 10/30

6:00 am-12:30 am

2 stops22h 30m

$780

Washington, D.C.Porto

IAD - OPO

IADOPO

Washington, D.C. Dulles Intl

Sat 8/15

10:35 pm-5:00 pm

1 stop13h 25m

Porto

Wed 9/2

7:00 am-3:10 pm

1 stop13h 10m

$833

Washington, D.C.Porto

IAD - OPO

IADOPO

Washington, D.C. Dulles Intl

Tue 8/18

12:29 pm-8:30 am

2 stops15h 01m

Porto

Wed 9/2

5:00 am-3:35 pm

1 stop15h 35m

$857

Washington, D.C.Porto

IAD - OPO

IADOPO

Washington, D.C. Dulles Intl

Mon 8/17

7:19 pm-3:25 pm

2 stops15h 06m

Porto

Mon 8/31

11:25 am-3:35 pm

1 stop33h 10m

$857
Quickest round-trip

Washington, D.C.Porto

IAD - OPO

IADOPO

Washington, D.C. Dulles Intl

Mon 8/17

10:35 pm-5:00 pm

1 stop13h 25m

Porto

Fri 8/28

9:00 am-3:10 pm

1 stop11h 10m

$891

Washington, D.C.Porto

IAD - OPO

IADOPO

Washington, D.C. Dulles Intl

Mon 8/31

3:45 pm-7:00 am

1 stop10h 15m

Porto

Tue 9/8

12:15 pm-11:26 am

2 stops28h 11m

$911

Washington, D.C.Porto

IAD - OPO

IADOPO

Washington, D.C. Dulles Intl

Tue 9/8

6:26 pm-3:25 pm

2 stops15h 59m

Porto

Tue 9/15

5:00 am-3:35 pm

1 stop15h 35m

$914

Washington, D.C.Porto

IAD - OPO

IADOPO

Washington, D.C. Dulles Intl

Tue 8/18

8:36 am-7:00 am

2 stops17h 24m

Porto

Sat 8/29

6:00 am-4:05 pm

1 stop15h 05m

$915

Washington, D.C.Porto

IAD - OPO

IADOPO

Washington, D.C. Dulles Intl

Mon 8/31

7:19 pm-3:25 pm

2 stops15h 06m

Porto

Tue 9/8

5:00 am-4:30 pm

2 stops16h 30m

$923

Washington, D.C.Porto

IAD - OPO

IADOPO

Washington, D.C. Dulles Intl

Tue 9/8

6:26 pm-3:25 pm

2 stops15h 59m

Porto

Mon 9/14

5:00 am-3:35 pm

1 stop15h 35m

$974

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/18

Showing 1-10 of 21 resultsSorted by cheapest first
1
2
3

Compare providers for flights from Dulles Intl to Porto

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Dulles Intl to Porto in July.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
AranGrantPrice Accuracy3 starsTrust Score*3 stars
OvagoPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy2 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-Porto flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Washington, D.C. Dulles Intl Airport-Porto flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Washington, D.C. Dulles Intl Airport-Porto flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-Porto flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Washington, D.C. Dulles Intl Airport-Porto flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Dulles Intl to Porto

Have a flexible travel schedule? Discover the best time to fly to Porto from Dulles Intl with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Washington, D.C. Dulles Intl Airport to Porto

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

To ensure you get the cheapest price possible for a flight from Washington, D.C. Dulles Intl Airport to Porto, you should look to book at least 63 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from Washington, D.C. Dulles Intl Airport to Porto?

Currently, October is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Porto (average of $530). Flying from Washington, D.C. Dulles Intl Airport to Porto in May is currently the most expensive (average of $1,227). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

How much does it cost to fly round-trip from Washington, D.C. Dulles Intl Airport to Porto?

Reviews of airlines servicing Porto

Get insights into the airlines that provide service to Porto. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Porto. Reviews last updated July 23, 2026.
Get a feel of what it's like to fly with Delta,United Airlines, andTAP AIR PORTUGAL from Washington, D.C. Dulles Intl Airport to Porto by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
7.8
Good
8,478 reviews

Comfort

7.8

Entertainment

7.8

Food

7.2

Boarding

8.1

Crew

8.5

Overall

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
Delta
7.8
Good
8,478 reviews
Delta
7.8
Good
8,478 reviews

Comfort

7.8

Entertainment

7.8

Food

7.2

Boarding

8.1

Crew

8.5

Overall

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
United Airlines
7.4
Good
10,021 reviews
Delta
7.8
Good
8,478 reviews

Comfort

7.8

Entertainment

7.8

Food

7.2

Boarding

8.1

Crew

8.5

Overall

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
TAP AIR PORTUGAL
7.2
Good
2,342 reviews
Delta
7.8
Good
8,478 reviews

Comfort

7.8

Entertainment

7.8

Food

7.2

Boarding

8.1

Crew

8.5

Overall

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
Iberia
7.0
Good
3,258 reviews
Delta
7.8
Good
8,478 reviews

Comfort

7.8

Entertainment

7.8

Food

7.2

Boarding

8.1

Crew

8.5

Overall

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
Lufthansa
6.8
Okay
8,159 reviews
Delta
7.8
Good
8,478 reviews

Comfort

7.8

Entertainment

7.8

Food

7.2

Boarding

8.1

Crew

8.5

Overall

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional

Related info for your journey

Find useful and relevant information for your journey from Dulles Intl to Porto. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Porto from Washington, D.C. Dulles Intl?

    Located just 6.8 mi from the city center, Porto is the airport most travelers will use when flying to Porto from Washington, D.C. Dulles Intl. Booking flights from Washington, D.C. Dulles Intl to Porto (OPO) should be relatively easy as there are 0 daily inbound flights from Washington, D.C. Dulles Intl from 6 different airlines.

  • How long is the flight from Washington, D.C. Dulles Intl Airport to Porto?

    Departing from Washington, D.C. Dulles Intl Airport to Porto will take you 13h 25m. The distance from Washington, D.C. Dulles Intl Airport to Porto is about 3537 mi. This flight may include one or multiple stops.

  • What are the cheapest airlines flying from Washington, D.C. Dulles Intl Airport to Porto round-trip?

    Currently priced at $477, KLM will fly you from Washington, D.C. Dulles Intl Airport to Porto and back. In addition to KLM, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from United Airlines and TAP AIR PORTUGAL - these airlines can fly you to your destination from $480 and $502, respectively. These flights start at 41% lower than the current average price 3 months from now.

  • Can I find deals for flights from Dulles Intl to Porto that include hotel bookings?

    Yes. In addition to deals on Dulles Intl to Porto flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Dulles Intl to Porto?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Dulles Intl to Porto.

  • Can I find deals for business class flights from Dulles Intl to Porto?

    Yes. Cheapflights offers flight deals from Dulles Intl to Porto by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Washington, D.C. Dulles Intl Airport to Porto?

    Currently, October is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Porto (average of $530). Flying from Washington, D.C. Dulles Intl Airport to Porto in May is currently the most expensive (average of $1,227). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near Porto?

Book flights to Porto if you plan to visit one of these locations
Vila Nova de Gaia
Arcos de Valdevez
Coimbra
Aveiro

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Alternative routes for Dulles Intl to Porto

See prices for flight routes from nearby airports that may be better suited for you.
Dulles Intl to Lisbon flights
Reagan-National to Lisbon flights
Baltimore to Lisbon flights
Dulles Intl to Funchal flights
Baltimore to Lajes flights

Top 6 airlines flying from Dulles Intl to Porto

Discover the top 6 airlines that operate flights from Dulles Intl to Porto. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated July 23, 2026.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest$477Average$883FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$480Average$973FlexibilityNo cancel feeOn-time69%
TAP AIR PORTUGALCheapest$502Average$796FlexibilityNo cancel feeOn-timeN/A
LufthansaCheapest$514Average$709FlexibilityNo cancel feeOn-time76%
DeltaCheapest$533Average$1,117FlexibilityNo cancel feeOn-timeN/A
IberiaCheapest$593Average$801FlexibilityNo cancel feeOn-time77%

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