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$151+ Cheap flights from Ontario to Milwaukee (ONT - MKE)

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 12/25. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — MKE
Jan 11 — Jan 181
Sun 1/11
Sun 1/18
1 adult, Economy
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Cheap flight deals from Ontario to Milwaukee

Cheapest flights from Ontario to Milwaukee
Explore the most affordable flight options available from Ontario to Milwaukee. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 12, 2025.

This Alaska Airlines deal was found by Cheapflights users on 12/10. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/316:00 amONT - MKE
1 stop30h 09mAlaska Airlines
Tue 1/63:05 pmMKE - ONT
1 stop11h 09mAlaska Airlines
Deal found 12/10$409
This Alaska Airlines deal was found by Cheapflights users on 12/10. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/316:00 amONT - MKE
1 stop30h 09mAlaska Airlines
Thu 1/83:53 pmMKE - ONT
1 stop21h 06mAlaska Airlines
Deal found 12/10$418
This United Airlines deal was found by Cheapflights users on 12/10. 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 12/315:05 amONT - MKE
1 stop7h 55mUnited Airlines
Thu 1/811:30 amMKE - ONT
2 stops12h 28mUnited Airlines
Deal found 12/10$432
This Delta deal was found by Cheapflights users on 12/10. 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 12/2710:29 pmONT - MKE
1 stop9h 04mDelta
Tue 1/611:03 amMKE - ONT
2 stops13h 48mDelta
Deal found 12/10$436
This Delta deal was found by Cheapflights users on 12/10. 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 12/2810:29 pmONT - MKE
1 stop9h 04mDelta
Tue 1/611:03 amMKE - ONT
2 stops13h 48mDelta
Deal found 12/10$441
This Delta deal was found by Cheapflights users on 12/10. 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 12/306:38 amONT - MKE
2 stops25h 50mDelta
Fri 1/911:03 amMKE - ONT
2 stops28h 53mDelta
Deal found 12/10$444
This Delta deal was found by Cheapflights users on 12/10. 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 12/306:38 amONT - MKE
2 stops25h 50mDelta
Thu 1/82:34 pmMKE - ONT
1 stop8h 31mDelta
Deal found 12/10$445
This United Airlines deal was found by Cheapflights users on 12/10. 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.
Sat 12/275:05 amONT - MKE
1 stop7h 55mUnited Airlines
Tue 1/64:05 pmMKE - ONT
1 stop6h 53mUnited Airlines
Deal found 12/10$447
This Delta deal was found by Cheapflights users on 12/10. 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 12/306:38 amONT - MKE
2 stops25h 50mDelta
Tue 1/611:03 amMKE - ONT
2 stops13h 48mDelta
Deal found 12/10$449
This Delta deal was found by Cheapflights users on 12/10. 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.
Wed 12/311:15 pmONT - MKE
1 stop6h 33mDelta
Tue 1/611:03 amMKE - ONT
2 stops13h 48mDelta
Deal found 12/10$452
This American Airlines deal was found by Cheapflights users on 12/10. 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.
Sat 12/2711:59 pmONT - MKE
1 stop9h 04mAmerican Airlines
Tue 1/66:40 amMKE - ONT
2 stops11h 25mAmerican Airlines
Deal found 12/10$457
This Delta deal was found by Cheapflights users on 12/10. 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.
Wed 12/311:15 pmONT - MKE
1 stop6h 33mDelta
Wed 1/77:45 amMKE - ONT
1 stop6h 31mDelta
Deal found 12/10$458

Find flight deals from Ontario to Milwaukee

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to Milwaukee (MKE). 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 December 12, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$294
(Alaska Airlines)

One-way from

$151
(Delta)

Popular in

January

Cheapest in

September

Average price

$406
Provider with most accurate pricing for Ontario-Milwaukee-Mitchell flight deals.
Search Deals
Provider most trusted by Cheapflights users for Ontario-Milwaukee-Mitchell flights.
Search Deals
From Ontario to Milwaukee-Mitchell
Search Deals
One-way flight from Ontario to Milwaukee-Mitchell
Search Deals
Highest demand for flights based on searches. 17% potential increase in price ($94 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 8% potential price decrease ($36 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Ontario to Milwaukee 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 December 12, 2025.
Use the filters below to find and compare flights from Ontario to Milwaukee that are best for you.

Fly from

Ontario

Fly to

Milwaukee

Route

Depart

Return

Price

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Thu 1/22

4:03 pm-2:57 pm

1 stop20h 54m

Milwaukee-Mitchell

Mon 1/26

3:53 pm-11:56 pm

1 stop10h 03m

$304

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Wed 2/25

6:14 am-2:51 pm

1 stop30h 37m

Milwaukee-Mitchell

Mon 3/2

3:47 pm-11:08 am

1 stop21h 21m

$304

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Wed 2/18

1:15 pm-11:48 pm

1 stop8h 33m

Milwaukee-Mitchell

Sat 2/21

7:20 am-12:07 pm

1 stop6h 47m

$334

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Wed 2/18

11:59 pm-10:59 am

1 stop9h 00m

Milwaukee-Mitchell

Sat 2/21

7:00 am-4:26 pm

2 stops11h 26m

$339

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Sat 1/17

1:24 pm-9:21 pm

1 stop5h 57m

Milwaukee-Mitchell

Thu 1/22

8:00 am-12:47 pm

1 stop6h 47m

$343

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Sat 1/17

5:30 am-1:10 pm

1 stop5h 40m

Milwaukee-Mitchell

Thu 1/22

6:05 am-10:05 am

1 stop6h 00m

$343

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Sat 1/17

12:41 pm-11:28 pm

1 stop8h 47m

Milwaukee-Mitchell

Thu 1/22

12:17 pm-9:05 pm

1 stop10h 48m

$343

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Sun 1/18

5:05 am-3:43 pm

2 stops8h 38m

Milwaukee-Mitchell

Thu 1/22

4:05 pm-8:58 pm

1 stop6h 53m

$348

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Sat 1/17

1:24 pm-9:21 pm

1 stop5h 57m

Milwaukee-Mitchell

Fri 1/23

4:05 pm-8:58 pm

1 stop6h 53m

$351

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Mon 1/5

1:11 pm-9:15 pm

1 stop6h 04m

$169

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/9

Showing 1-10 of 18 results
1
2

Compare providers for flights from Ontario to Milwaukee

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 Ontario to Milwaukee in December.
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 Ontario-Milwaukee flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Ontario-Milwaukee flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Ontario-Milwaukee flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Ontario-Milwaukee 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 Ontario-Milwaukee 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 Ontario to Milwaukee

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

What is the cheapest month to book a flight from Ontario to Milwaukee?

Currently, March is the cheapest month in which you can book a flight from Ontario to Milwaukee (average of $77). Flying from Ontario to Milwaukee in October is currently the most expensive (average of $147). 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 ONT to MKE?

Find hourly flight availability from Ontario to Milwaukee. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated December 12, 2025.

One of the essential ways to save on airfare from Ontario to Milwaukee is to remain as flexible as possible. Flights that are at noon tend to be the most expensive. A flight in the evening could potentially save you up to 32% on airfare.

How much does it cost to fly round-trip from Ontario to Milwaukee?

Reviews of airlines servicing Milwaukee

Get insights into the airlines that provide service to Milwaukee. 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 Milwaukee. Reviews last updated December 12, 2025.
Read reviews from past customers who have flown Southwest, Delta, and United Airlines from Ontario to Milwaukee. 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.
Southwest
7.9
Good
4,253 reviews

Comfort

8.0

Crew

8.6

Overall

7.9

Boarding

8.1

Food

7.0

Entertainment

7.5

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
Southwest
7.9
Good
4,253 reviews
Southwest
7.9
Good
4,253 reviews

Comfort

8.0

Crew

8.6

Overall

7.9

Boarding

8.1

Food

7.0

Entertainment

7.5

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
Delta
7.9
Good
8,008 reviews
Southwest
7.9
Good
4,253 reviews

Comfort

8.0

Crew

8.6

Overall

7.9

Boarding

8.1

Food

7.0

Entertainment

7.5

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
United Airlines
7.4
Good
9,095 reviews
Southwest
7.9
Good
4,253 reviews

Comfort

8.0

Crew

8.6

Overall

7.9

Boarding

8.1

Food

7.0

Entertainment

7.5

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
American Airlines
7.2
Good
11,050 reviews
Southwest
7.9
Good
4,253 reviews

Comfort

8.0

Crew

8.6

Overall

7.9

Boarding

8.1

Food

7.0

Entertainment

7.5

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.

Related info for your journey

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

    A quick flight from Ontario to Milwaukee can take about 8h 33m. Alaska Airlines provides one of the quickest options available for as low as $334. The distance between Ontario and Milwaukee is about 1707 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines flying from Ontario to Milwaukee round-trip?

    Delta, at $253, was found to be the cheapest airline from Ontario to Milwaukee.Alternate airlines to your destination round-trip include American Airlines and United Airlines. Delta is currently priced 44% below the average price you’ll pay for this route.

  • What are the cheapest airlines to fly from Ontario to Milwaukee one-way?

    For one-way options, check prices for Frontier. According to our data, you can fly for as low as $67. Users have also found prices from $154 and $171 on American Airlines and Southwest, respectively.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Ontario to Milwaukee 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 Ontario to Milwaukee?

    Currently, March is the cheapest month in which you can book a flight from Ontario to Milwaukee (average of $77). Flying from Ontario to Milwaukee in October is currently the most expensive (average of $147). 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 Milwaukee?

Book flights to Milwaukee if you plan to visit one of these locations
Sheboygan
New Berlin
Oak Creek
Wauwatosa

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Alternative routes for Ontario to Milwaukee

See prices for flight routes from nearby airports that may be better suited for you.
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Top 4 airlines flying from Ontario to Milwaukee

Discover the top 4 airlines that operate flights from Ontario to Milwaukee. 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 December 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$253Average$391FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$276Average$399FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$309Average$426FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$330Average$428FlexibilityNo cancel feeOn-time63%

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