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$181+ 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 1/17. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — ONT
dec. 21 — dec. 281
søn. 12/21
søn. 12/28
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 november 21, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$307
(Delta)

One-way from

$181
(United Airlines)

Popular in

February

Cheapest in

May

Average price

$460
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. 12% potential increase in price ($78 potential increase over avg. RT price).
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Cheapest flight prices on average. 7% potential price decrease ($36 potential savings vs. average RT price).
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Average for round-trip flights in November 2025
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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 november 21, 2025.

This Delta deal was found by Cheapflights users on 11/18. 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.
tir. 12/96:08 amPWM - ONT
2 stops13h 01mDelta
lør. 12/136:00 amONT - PWM
2 stops13h 23mDelta
Deal found 11/18$307
This Southwest deal was found by Cheapflights users on 11/18. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
søn. 12/1411:50 amPWM - ONT
1 stop8h 25mSouthwest
tor. 12/1810:50 amONT - PWM
1 stop10h 30mSouthwest
Deal found 11/18$350
This American Airlines deal was found by Cheapflights users on 11/18. 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.
søn. 12/145:34 amPWM - ONT
2 stops11h 25mAmerican Airlines
tor. 12/189:53 amONT - PWM
2 stops10h 02mAmerican Airlines
Deal found 11/18$369
This American Airlines deal was found by Cheapflights users on 11/18. 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.
tir. 12/95:34 amPWM - ONT
2 stops11h 21mAmerican Airlines
tor. 12/116:00 amONT - PWM
2 stops14h 37mAmerican Airlines
Deal found 11/18$384
This Delta deal was found by Cheapflights users on 11/20. 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.
fre. 12/54:53 pmPWM - ONT
2 stops10h 05mDelta
tir. 12/97:05 amONT - PWM
2 stops13h 16mDelta
Deal found 11/20$393
This Southwest deal was found by Cheapflights users on 11/18. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
man. 12/85:30 amPWM - ONT
2 stops12h 00mSouthwest
tor. 12/118:55 amONT - PWM
2 stops10h 20mSouthwest
Deal found 11/18$403
This Southwest deal was found by Cheapflights users on 11/18. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
man. 12/85:30 amPWM - ONT
2 stops12h 10mSouthwest
fre. 12/129:15 amONT - PWM
2 stops12h 05mSouthwest
Deal found 11/18$424
This American Airlines deal was found by Cheapflights users on 11/18. 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.
søn. 12/75:34 amPWM - ONT
2 stops11h 25mAmerican Airlines
lør. 12/136:00 amONT - PWM
2 stops12h 42mAmerican Airlines
Deal found 11/18$470
This United Airlines deal was found by Cheapflights users on 11/20. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
fre. 12/56:00 amPWM - ONT
3 stops19h 49mUnited Airlines
tir. 12/95:05 amONT - PWM
2 stops10h 49mUnited Airlines
Deal found 11/20$475
This United Airlines deal was found by Cheapflights users on 11/18. 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.
tir. 12/910:35 amPWM - ONT
3 stops15h 14mUnited Airlines
lør. 12/135:05 amONT - PWM
2 stops15h 07mUnited Airlines
Deal found 11/18$481
This American Airlines deal was found by Cheapflights users on 11/18. 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.
søn. 12/75:34 amPWM - ONT
2 stops15h 44mAmerican Airlines
tor. 12/116:00 amONT - PWM
2 stops14h 37mAmerican Airlines
Deal found 11/18$493

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 november 21, 2025.
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

tir. 12/9

6:08 am-4:09 pm

2 stops13h 01m

Ontario

lør. 12/13

6:00 am-10:23 pm

2 stops13h 23m

$307

PortlandOntario

PWM - ONT

PWMONT

Portland

søn. 12/14

11:50 am-5:15 pm

1 stop8h 25m

Ontario

tor. 12/18

8:30 am-12:20 am

2 stops12h 50m

$350

PortlandOntario

PWM - ONT

PWMONT

Portland

tir. 12/9

5:34 am-1:55 pm

2 stops11h 21m

Ontario

tor. 12/11

6:00 am-11:37 pm

2 stops14h 37m

$384

PortlandOntario

PWM - ONT

PWMONT

Portland

tor. 4/30

5:30 am-2:20 pm

2 stops11h 50m

Ontario

søn. 5/3

9:55 pm-2:10 pm

1 stop13h 15m

$390

PortlandOntario

PWM - ONT

PWMONT

Portland

fre. 12/5

4:53 pm-11:58 pm

2 stops10h 05m

Ontario

tir. 12/9

7:05 am-11:21 pm

2 stops13h 16m

$393

PortlandOntario

PWM - ONT

PWMONT

Portland

lør. 5/2

6:00 am-11:20 am

1 stop8h 20m

Ontario

tir. 5/5

7:00 am-11:59 pm

2 stops13h 59m

$394

PortlandOntario

PWM - ONT

PWMONT

Portland

ons. 4/29

2:18 pm-10:09 pm

1 stop10h 51m

Ontario

søn. 5/3

11:25 pm-1:23 pm

1 stop10h 58m

$410

PortlandOntario

PWM - ONT

PWMONT

Portland

fre. 5/1

6:00 am-11:20 am

1 stop8h 20m

Ontario

man. 5/4

10:59 pm-11:55 am

2 stops9h 56m

$413

PortlandOntario

PWM - ONT

PWMONT

Portland

man. 12/8

5:30 am-2:30 pm

2 stops12h 00m

Ontario

fre. 12/12

10:50 am-12:20 am

1 stop10h 30m

$425

PortlandOntario

PWM - ONT

PWMONT

Portland

tor. 4/30

2:18 pm-10:09 pm

1 stop10h 51m

Ontario

søn. 5/3

11:25 pm-1:23 pm

1 stop10h 58m

$449

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/19

Showing 1-10 of 23 results
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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 November.
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 April is currently the most expensive (average of $173). 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 november 21, 2025.
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
8,002 reviews

Crew

8.5

Comfort

7.9

Food

7.3

Overall

7.9

Entertainment

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
8,002 reviews
Delta
7.9
Good
8,002 reviews

Crew

8.5

Comfort

7.9

Food

7.3

Overall

7.9

Entertainment

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
11,047 reviews
Delta
7.9
Good
8,002 reviews

Crew

8.5

Comfort

7.9

Food

7.3

Overall

7.9

Entertainment

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, Southwest, and American Airlines fly from Portland, Maine to Ontario in about 8h 25m. The time it takes to get you to your destination can typically vary by up to 4h 36m. 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?

    American Airlines, at $279, was found to be the cheapest airline from Portland, Maine to Ontario. An alternate airline flying to your destination would be Delta. Users have found that American Airlines is 49% cheaper than the other options available to this destination.

  • 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 April is currently the most expensive (average of $173). 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

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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 november 21, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$279Average$593FlexibilityNo cancel feeOn-time71%
DeltaCheapest$302Average$442FlexibilityNo cancel feeOn-timeN/A

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