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$149+ Cheap flights from Portland, ME to Ontario (PWM - ONT)

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 4/11. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — ONT
Feb 7 — Feb 141
Sat 2/7
Sat 2/14
1 adult, Economy
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Cheap flight deals from Portland to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from Portland (PWM) to Ontario (ONT). 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 January 8, 2026.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$351
(American Airlines)

One-way from

$149
(Delta)

Popular in

December

Cheapest in

September

Average price

$377
Provider with most accurate pricing for Portland-Ontario flight deals.
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Provider most trusted by Cheapflights users for Portland-Ontario flights.
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From Portland to Ontario
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One-way flight from Portland to Ontario
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Highest demand for flights based on searches. 6% potential increase in price ($30 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($12 potential savings vs. average RT price).
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Average for round-trip flights in January 2026
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Find flight deals from Portland to Ontario

Cheapest flights from Portland to Ontario
Explore the most affordable flight options available from Portland to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 8, 2026.

This Delta deal was found by Cheapflights users on 1/8. 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.
Fri 1/305:30 amPWM - ONT
1 stop9h 01mDelta
Tue 2/310:30 pmONT - PWM
2 stops10h 33mDelta
Deal found 1/8$302
This Delta deal was found by Cheapflights users on 1/8. 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.
Thu 3/194:48 pmPWM - ONT
2 stops10h 02mDelta
Mon 3/2310:25 pmONT - PWM
2 stops9h 39mDelta
Deal found 1/8$339
This American Airlines deal was found by Cheapflights users on 1/8. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/2612:29 pmPWM - ONT
2 stops12h 38mAmerican Airlines
Sun 3/111:58 pmONT - PWM
2 stops9h 01mAmerican Airlines
Deal found 1/8$351
This American Airlines deal was found by Cheapflights users on 1/5. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 1/237:00 amPWM - ONT
2 stops13h 22mAmerican Airlines
Mon 1/2611:59 pmONT - PWM
2 stops12h 32mAmerican Airlines
Deal found 1/5$361
This United Airlines deal was found by Cheapflights users on 1/6. 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 5/54:45 pmPWM - ONT
1 stop8h 41mUnited Airlines
Sat 5/95:05 amONT - PWM
1 stop7h 30mUnited Airlines
Deal found 1/6$374
This Delta deal was found by Cheapflights users on 1/6. 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.
Fri 1/235:30 amPWM - ONT
1 stop9h 01mDelta
Tue 2/2410:20 pmONT - PWM
2 stops9h 58mDelta
Deal found 1/6$388
This United Airlines deal was found by Cheapflights users on 1/6. 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.
Fri 10/304:48 pmPWM - ONT
1 stop8h 38mUnited Airlines
Wed 11/45:00 amONT - PWM
2 stops10h 13mUnited Airlines
Deal found 1/6$402
This Delta deal was found by Cheapflights users on 1/6. 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.
Sun 1/185:30 amPWM - ONT
1 stop9h 01mDelta
Mon 2/2310:20 pmONT - PWM
2 stops9h 58mDelta
Deal found 1/6$441
This United Airlines deal was found by Cheapflights users on 1/5. 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.
Wed 3/184:23 pmPWM - ONT
1 stop9h 02mUnited Airlines
Tue 3/2411:59 pmONT - PWM
2 stops10h 58mUnited Airlines
Deal found 1/5$463
This Priceline deal was found by Cheapflights users on 1/7. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/262:17 pmPWM - ONT
1 stop10h 12mJetBlue
Sun 10/410:56 pmONT - PWM
1 stop11h 26mJetBlue
Deal found 1/7$495

Cheapflights Fare Finder

 
Customize your flight search to find flights from Portland to Ontario 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 January 8, 2026.
Use the filters below to find and compare flights from Portland to Ontario that are best for you.

Fly from

Portland

Fly to

Ontario

Route

Depart

Return

Price

PortlandOntario

PWM - ONT

PWMONT

Portland

Fri 1/30

5:30 am-11:31 am

1 stop9h 01m

Ontario

Tue 2/3

10:30 pm-12:03 pm

2 stops10h 33m

$302

PortlandOntario

PWM - ONT

PWMONT

Portland

Tue 5/5

4:45 pm-10:26 pm

1 stop8h 41m

Ontario

Sat 5/9

5:05 am-3:35 pm

1 stop7h 30m

$374

PortlandOntario

PWM - ONT

PWMONT

Portland

Thu 1/22

5:30 am-11:31 am

1 stop9h 01m

Ontario

Mon 2/23

10:20 pm-11:18 am

2 stops9h 58m

$388

PortlandOntario

PWM - ONT

PWMONT

Portland

Fri 1/23

5:30 am-11:31 am

1 stop9h 01m

Ontario

Tue 2/24

10:20 pm-11:18 am

2 stops9h 58m

$388

PortlandOntario

PWM - ONT

PWMONT

Portland

Fri 1/23

5:30 am-11:31 am

1 stop9h 01m

Ontario

Mon 2/23

10:20 pm-11:18 am

2 stops9h 58m

$388

PortlandOntario

PWM - ONT

PWMONT

Portland

Fri 1/23

5:30 am-11:31 am

1 stop9h 01m

Ontario

Mon 1/26

10:30 pm-1:45 pm

2 stops12h 15m

$388

PortlandOntario

PWM - ONT

PWMONT

Portland

Thu 1/22

5:30 am-11:31 am

1 stop9h 01m

Ontario

Tue 2/24

10:20 pm-11:18 am

2 stops9h 58m

$388

PortlandOntario

PWM - ONT

PWMONT

Portland

Thu 3/19

5:18 am-11:40 am

1 stop9h 22m

Ontario

Mon 3/23

10:25 pm-11:04 am

2 stops9h 39m

$434

PortlandOntario

PWM - ONT

PWMONT

Portland

Mon 1/19

5:30 am-11:31 am

1 stop9h 01m

Ontario

Mon 2/23

10:20 pm-11:18 am

2 stops9h 58m

$441

PortlandOntario

PWM - ONT

PWMONT

Portland

Wed 3/18

4:23 pm-10:25 pm

1 stop9h 02m

Ontario

Tue 3/24

11:59 pm-1:57 pm

2 stops10h 58m

$463

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/7

Showing 1-10 of 20 results
1
2

Compare providers for flights from Portland to Ontario

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 Portland to Ontario in January.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 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 Portland, Maine-Ontario flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Portland, Maine-Ontario flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Portland, Maine-Ontario flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Portland, Maine-Ontario flights, Cheapflights users trust eDreams the most. eDreams 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-Ontario 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 Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario 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.

Cheapflights Insights

Everything you need to know about your flight from Portland to Ontario

What is the cheapest month to book a flight from Portland, Maine to Ontario?

Currently, August is the cheapest month in which you can book a flight from Portland, Maine to Ontario (average of $115). Flying from Portland, Maine to Ontario in December is currently the most expensive (average of $179). 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.

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated January 8, 2026.
Read reviews from past customers who have flown Delta and American Airlines from Portland to Ontario. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
7.9
Good
8,025 reviews

Entertainment

7.8

Food

7.2

Comfort

7.9

Crew

8.5

Overall

7.9

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
Delta
7.9
Good
8,025 reviews
Delta
7.9
Good
8,025 reviews

Entertainment

7.8

Food

7.2

Comfort

7.9

Crew

8.5

Overall

7.9

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
American Airlines
7.2
Good
11,095 reviews
Delta
7.9
Good
8,025 reviews

Entertainment

7.8

Food

7.2

Comfort

7.9

Crew

8.5

Overall

7.9

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Related info for your journey

Find useful and relevant information for your journey from Portland to Ontario. 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 Ontario?

    Airlines like Delta and United Airlines fly from Portland, Maine to Ontario in about 8h 41m. The time it takes to get you to your destination can typically vary by up to 20m. There are 2590 mi between Portland, Maine and Ontario. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines flying from Portland, Maine to Ontario round-trip?

    Delta, at $196, was found to be the cheapest airline from Portland, Maine to Ontario. An alternate airline flying to your destination would be American Airlines.

  • What are the cheapest airlines to fly from Portland, Maine to Ontario one-way?

    The cheapest airlines for a one-way flight from Portland, Maine to Ontario are United Airlines ($118), Delta ($148), and Southwest ($180).

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Portland to Ontario 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 Portland, Maine to Ontario?

    Currently, August is the cheapest month in which you can book a flight from Portland, Maine to Ontario (average of $115). Flying from Portland, Maine to Ontario in December is currently the most expensive (average of $179). 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.

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Top 2 airlines flying from Portland to Ontario

Discover the top 2 airlines that operate flights from Portland to Ontario. 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 January 8, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$259Average$423FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$279Average$513FlexibilityNo cancel feeOn-time71%

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