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Shannon

$738+ Cheap flights from Portland, ME (PWM) to Shannon (SNN)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 9/21. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — SNN
Sep 2 — Sep 91
Wed 9/2
Wed 9/9
1 adult, Economy
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Cheap flight deals from Portland to Shannon

Cheapest flights from Portland to Shannon
Explore the most affordable flight options available from Portland to Shannon. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 3, 2026.

This United Airlines deal was found by Cheapflights users on 7/31. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/216:06 am
PWM
-
SNN
1 stop23h 09m
United Airlines
Thu 10/112:30 pm
SNN
-
PWM
1 stop12h 52m
United Airlines
Deal found 7/31$738
This United Airlines deal was found by Cheapflights users on 7/29. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/277:40 am
PWM
-
SNN
1 stop18h 50m
United Airlines
Mon 8/3112:30 pm
SNN
-
PWM
1 stop16h 02m
United Airlines
Deal found 7/29$739
This United Airlines deal was found by Cheapflights users on 8/2. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/17:35 am
PWM
-
SNN
1 stop18h 55m
United Airlines
Mon 9/712:30 pm
SNN
-
PWM
1 stop10h 59m
United Airlines
Deal found 8/2$757
This United Airlines deal was found by Cheapflights users on 8/2. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/110:45 am
PWM
-
SNN
1 stop18h 30m
United Airlines
Tue 9/812:30 pm
SNN
-
PWM
1 stop16h 02m
United Airlines
Deal found 8/2$758
This United Airlines deal was found by Cheapflights users on 7/30. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/305:00 pm
PWM
-
SNN
1 stop33h 30m
United Airlines
Mon 8/109:30 am
SNN
-
PWM
1 stop17h 11m
United Airlines
Deal found 7/30$774

Find flight deals from Portland to Shannon

Discover tips and strategies to find the most affordable flight options for your journey from Portland (PWM) to Shannon (SNN). 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 August 3, 2026.

Most accurate provider

Expedia
1 star

Most trusted provider

Expedia
3 stars

Round-trip from

$738
(United Airlines)
Provider with most accurate pricing for Portland-Shannon flight deals.
Search Deals
Provider most trusted by Cheapflights users for Portland-Shannon flights.
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From Portland to Shannon
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Cheapflights Fare Finder

 
Customize your flight search to find flights from Portland to Shannon 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 August 3, 2026.
Use the filters below to find and compare flights from Portland to Shannon that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip
Quickest round-trip

PortlandShannon

PWM - SNN

PWMSNN

Portland

Sat 10/10

6:55 pm-10:15 am

1 stop10h 20m

Shannon

Tue 10/20

12:30 pm-6:12 pm

1 stop10h 42m

$739

PortlandShannon

PWM - SNN

PWMSNN

Portland

Mon 9/14

6:53 pm-10:15 am

1 stop10h 22m

Shannon

Mon 9/21

9:30 am-9:23 pm

1 stop16h 53m

$739

PortlandShannon

PWM - SNN

PWMSNN

Portland

Sun 9/13

6:53 pm-10:15 am

1 stop10h 22m

Shannon

Sun 9/20

9:30 am-5:54 pm

1 stop13h 24m

$739

PortlandShannon

PWM - SNN

PWMSNN

Portland

Mon 9/21

6:00 am-10:15 am

2 stops23h 15m

Shannon

Thu 10/1

12:30 pm-8:22 pm

1 stop12h 52m

$742

PortlandShannon

PWM - SNN

PWMSNN

Portland

Thu 8/27

5:15 am-7:30 am

2 stops21h 15m

Shannon

Mon 8/31

12:30 pm-6:29 pm

1 stop10h 59m

$743

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/29

Sorted by cheapest first
  • Most accurate provider: When it comes to deals on Portland, Maine-Shannon, Clare flights, users find the pricing of Expedia to be most consistent on Cheapflights vs. Expedia Users can find the same prices on Portland, Maine-Shannon, Clare flight deals on Cheapflights vs. Expedia <90% of the time. Price accuracy is based on data collected from Portland, Maine-Shannon, Clare flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Portland, Maine-Shannon, Clare flights, Cheapflights users trust Expedia the most. Expedia 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 Portland, Maine-Shannon, Clare 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 Portland to Shannon

Have a flexible travel schedule? Discover the best time to fly to Shannon from Portland 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.

Reviews of airlines servicing Shannon

Get insights into the airlines that provide service to Shannon. 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 Shannon. Reviews last updated August 3, 2026.
Peruse reviews from past customers who have flown with United Airlines from Portland to Shannon to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
10,058 reviews

Overall

7.4

Entertainment

7.1

Comfort

7.3

Food

6.7

Boarding

7.7

Crew

8.1

Reviews

1 / 20
2.0
Mediocre

Dawn,Aug 2026

ORD - DEN

I missed my connecting flight because our plane took off ten minutes late and then when we got to the airport another plane was in our shoot waiting to get fueled up and that took 30 minutes so I missed my connecting flight. I asked if I could get off and they assured me the plane would most likely wait for me since they know what time the planes get in because of an app. I was not happy. I had to wait till 7:25 to board the next flight and then that was delayed. Gates changed till 9:20. Terrible
United Airlines
7.4
Good
10,058 reviews
United Airlines
7.4
Good
10,058 reviews

Overall

7.4

Entertainment

7.1

Comfort

7.3

Food

6.7

Boarding

7.7

Crew

8.1

Reviews

1 / 20
2.0
Mediocre

Dawn,Aug 2026

ORD - DEN

I missed my connecting flight because our plane took off ten minutes late and then when we got to the airport another plane was in our shoot waiting to get fueled up and that took 30 minutes so I missed my connecting flight. I asked if I could get off and they assured me the plane would most likely wait for me since they know what time the planes get in because of an app. I was not happy. I had to wait till 7:25 to board the next flight and then that was delayed. Gates changed till 9:20. Terrible

Related info for your journey

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

  • How long is the flight from Portland, Maine to Shannon, Clare?

    United Airlines can get you from Portland, Maine to Shannon, Clare in just under 18h 30m. Your travel time can differ by up to . Airlines will cover a distance of 2805 mi.

  • What is the cheapest airline to fly from Portland, Maine to Shannon, Clare round-trip?

    According to our current data, United Airlines ($606), offers the cheapest pricing from Portland, Maine to Shannon, Clare.

  • Can I find deals for flights from Portland to Shannon that include hotel bookings?

    Yes. In addition to deals on Portland to Shannon flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Portland to Shannon?

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

  • Can I find deals for business class flights from Portland to Shannon?

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

See more FAQs

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Alternative routes for Portland to Shannon

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Top airline flying from Portland to Shannon

Discover the top airline that operate flights from Portland to Shannon. 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 August 3, 2026.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$606Average$956FlexibilityNo cancel feeOn-time69%

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