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Cheap flights from Portsmouth to Washington, D.C. Dulles Intl Airport from £337

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 11/11. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — IAD
20 Aug — 27 Aug1
1 adult

Cheap flight deals from Portsmouth to Dulles Intl

Keep the following information in mind while searching for Portsmouth to Dulles Intl flight deals. Data was last updated 15 August 2025.

Round-trip from

£516

One-way from

£337

Popular in

July

Cheapest in

February

Average price

£603
27/9-4/10
  • 27/9-4/10
  • 4 total stops
  • 35h 30m total
  • Portsmouth to Washington, D.C.
Search Deals
11/11
  • 11/11
  • 3 total stops
  • 48h 05m total
  • Portsmouth to Washington, D.C.
Search Deals
Highest demand for flights based on searches. 11% potential increase in price (£51 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease (£8 potential savings vs. average return price).
Search Deals
Average for round-trip flights in August 2025
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Find flight deals from Portsmouth to Dulles Intl

Cheapest flights from Portsmouth to Dulles Intl
Explore the most affordable flight options available from Portsmouth to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 15 August 2025.

Sat 27/909:40SOU - IAD
2 stops17h 30mMultiple Airlines
Sat 4/1020:30IAD - SOU
2 stops18h 00mMultiple Airlines
Deal found 12/8£516
Sat 27/909:40SOU - IAD
1 stop11h 10mAer Lingus
Sat 4/1020:25IAD - SOU
1 stop18h 05mAer Lingus
Deal found 13/8£623
Sat 27/909:20SOU - IAD
1 stop11h 15mVirgin Atlantic
Sat 4/1018:16IAD - SOU
2 stops18h 34mVirgin Atlantic
Deal found 12/8£630
Sat 27/909:20SOU - IAD
1 stop11h 15mDelta
Sat 4/1012:08IAD - SOU
2 stops15h 37mDelta
Deal found 13/8£631
Wed 27/809:10SOU - IAD
1 stop15h 20mBritish Airways
Wed 3/917:20IAD - SOU
1 stop18h 15mBritish Airways
Deal found 13/8£802
Sat 13/909:40SOU - IAD
1 stop11h 10mBritish Airways
Sat 22/1121:45IAD - SOU
2 stops12h 40mBritish Airways
Deal found 14/8£804

Cheapflights Fare Finder

 
Customise your flight search to find flights from Portsmouth to Dulles Intl 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 858,174 searches. Data last updated 15 August 2025.
Use the filters below to find and compare flights from Portsmouth to Washington, D.C. Dulles Intl Airport that are best for you.

Fly from

Portsmouth

Fly to

Dulles Intl

Route

Depart

Return

Price

SouthamptonWashington, D.C.

SOU - IAD

SOUIAD

Southampton Eastleigh

Sat 27/9

09:40-22:10

2 stops17h 30m

Washington, D.C. Dulles Intl

Sat 4/10

20:30-19:30

2 stops18h 00m

£516

SouthamptonWashington, D.C.

SOU - IAD

SOUIAD

Southampton Eastleigh

Sat 27/9

09:40-15:50

1 stop11h 10m

Washington, D.C. Dulles Intl

Sat 4/10

20:25-19:30

1 stop18h 05m

£623

SouthamptonWashington, D.C.

SOU - IAD

SOUIAD

Southampton Eastleigh

Sat 27/9

09:20-15:35

1 stop11h 15m

Washington, D.C. Dulles Intl

Sat 4/10

18:16-17:50

2 stops18h 34m

£630

SouthamptonWashington, D.C.

SOU - IAD

SOUIAD

Southampton Eastleigh

Sat 27/9

09:20-15:35

1 stop11h 15m

Washington, D.C. Dulles Intl

Sat 4/10

12:08-08:45

2 stops15h 37m

£631

SouthamptonWashington, D.C.

SOU - IAD

SOUIAD

Southampton Eastleigh

Wed 27/8

09:10-19:30

1 stop15h 20m

Washington, D.C. Dulles Intl

Wed 3/9

17:20-16:35

1 stop18h 15m

£802

SouthamptonWashington, D.C.

SOU - IAD

SOUIAD

Southampton Eastleigh

Sat 13/9

09:40-15:50

1 stop11h 10m

Washington, D.C. Dulles Intl

Sat 22/11

21:45-15:25

2 stops12h 40m

£804

SouthamptonWashington, D.C.

SOU - IAD

SOUIAD

Southampton Eastleigh

Tue 11/11

20:10-15:15

3 stops48h 05m

£337

SouthamptonWashington, D.C.

SOU - IAD

SOUIAD

Southampton Eastleigh

Tue 11/11

09:30-19:30

1 stop15h 00m

£473

SouthamptonWashington, D.C.

SOU - IAD

SOUIAD

Southampton Eastleigh

Mon 5/1

20:10-15:35

1 stop24h 25m

£871

SouthamptonWashington, D.C.

SOU - IAD

SOUIAD

Southampton Eastleigh

Sun 4/1

20:10-15:35

1 stop24h 25m

£871

Flights are sorted by cheapest return flights first.

Deals found on 14/8

Showing 1-10 of 13 results
1
2

Best time to book a flight from Portsmouth to Dulles Intl

Have a flexible travel schedule? Discover the best time to fly to Dulles Intl from Portsmouth with our price prediction graph.
Estimated return 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 Portsmouth to Washington, D.C. Dulles Intl Airport

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

Currently, January is the cheapest month in which you can book a flight from Portsmouth to Washington, D.C. Dulles Intl Airport (average of £599). Flying from Portsmouth to Washington, D.C. Dulles Intl Airport in July is currently the most expensive (average of £947). 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.

What is the cheapest time of day to fly from P0R to IAD?

Find hourly flight availability from Portsmouth to Dulles Intl. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 15 August 2025.

When flying from Portsmouth to Washington, D.C. Dulles Intl Airport, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

What is the cheapest day to fly from Portsmouth to Washington, D.C. Dulles Intl Airport?

Use this chart to determine the cheapest time to fly return from Portsmouth to Dulles Intl. Price data was last updated on 16 December 2024.

Travellers seeking maximum savings on their Portsmouth to Washington, D.C. Dulles Intl Airport flight should consider departing on Thursday mornings when fares are most often at their lowest. Thursday mornings flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Portsmouth to Washington, D.C. Dulles Intl Airport

Explore weekly flight availability from Portsmouth to Dulles Intl. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated 15 August 2025.

The most flights from P0R to IAD are scheduled on a Monday (28 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (13 on average).

Related info for your journey

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

  • What are the most reliable airlines from Portsmouth to Washington, D.C. Dulles Intl Airport?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Portsmouth to Washington, D.C. Dulles Intl Airport on time: KLM (74%), Air France (74%), Delta (74%).

  • What are the cheapest flights from Portsmouth to Washington, D.C. Dulles Intl Airport?

    The cheapest flight price from Portsmouth to Washington, D.C. Dulles Intl Airport is £383. On average you can expect to pay £1,388. The most popular route, (Southampton Eastleigh - Washington, D.C. Dulles Intl), can usually be booked for £742.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Portsmouth to Dulles Intl 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 Portsmouth to Washington, D.C. Dulles Intl Airport?

    Currently, January is the cheapest month in which you can book a flight from Portsmouth to Washington, D.C. Dulles Intl Airport (average of £599). Flying from Portsmouth to Washington, D.C. Dulles Intl Airport in July is currently the most expensive (average of £947). 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

Travelling to a place near Washington, D.C. Dulles Intl Airport?

Book flights to Washington, D.C. Dulles Intl Airport if you plan to visit one of these locations
Silver Spring
Hanover
Oxon Hill
Woodbridge
Arlington
College Park
Laurel
Tysons

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Alternative routes for Portsmouth to Dulles Intl

See prices for flight routes from nearby airports that may be better suited for you.
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Edinburgh to Reagan-National flights
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Birmingham to Dulles Intl flights
Leeds to Reagan-National flights
Newcastle upon Tyne to Baltimore flights
Newcastle upon Tyne to Reagan-National flights
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Birmingham to Baltimore flights
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Southampton to Baltimore flights
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Southampton to Reagan-National flights
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Norwich to Reagan-National flights
Norwich to Dulles Intl flights
Grimsby to Dulles Intl flights
Grimsby to Reagan-National flights
East Midlands to Baltimore flights
Exeter to Dulles Intl flights
Southend to Dulles Intl flights
Newquay to Baltimore flights
Grimsby to Baltimore flights
Doncaster to Dulles Intl flights
Doncaster to Baltimore flights

Top 10 airlines flying from Portsmouth to Dulles Intl

Discover the top 10 airlines that operate flights from Portsmouth to Dulles Intl. 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 858,174 searches. Data last updated 15 August 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest£187Average£529FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
PLAYCheapest£246Average£384FlexibilityNo cancel feeOn-timeN/A
Search PLAY flights
TAP AIR PORTUGALCheapest£350Average£511FlexibilityNo cancel feeOn-timeN/A
Search TAP AIR PORTUGAL flights
IcelandairCheapest£370Average£515FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
LufthansaCheapest£434Average£614FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
FinnairCheapest£434Average£608FlexibilityNo cancel feeOn-time76%
Search Finnair flights
Air FranceCheapest£434Average£575FlexibilityNo cancel feeOn-time77%
Search Air France flights
Scandinavian AirlinesCheapest£434Average£568FlexibilityNo cancel feeOn-time77%
Search Scandinavian Airlines flights
United AirlinesCheapest£442Average£713FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Virgin AtlanticCheapest£449Average£620FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from Portsmouth to Dulles Intl?

When you search for this flight from Portsmouth to Dulles Intl, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.

Why should you use Cheapflights to find cheap flight tickets from Portsmouth to Dulles Intl?

Cheapflights simply makes it quick and affordable to book flights from Portsmouth to Dulles Intl by bringing together all flight options from hundreds of airlines and agencies online — and put it in one place for you to choose from. Plus, Cheapflights is 100% free to use for all.

Can Cheapflights find flights from Portsmouth to Dulles Intl with no change fees?

Yes! Cheapflights helps users easily find flights from Portsmouth to Dulles Intl with no change fees.

Can Cheapflights notify me if prices for flights from Portsmouth to Dulles Intl become cheaper?

Of course! You can now track prices for flights from Portsmouth to Dulles Intl and get an alert from Cheapflights when they change. Have a valid email address ready and click the bell icon next to the flight deals above to set up your price alerts.

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