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Milwaukee

$117+ 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 11/17. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — MKE
Nov 27 — Dec 41
Thu 11/27
Thu 12/4
1 adult, Economy
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Cheapflights Tip: The best prices from Ontario to Milwaukee-Mitchell are usually found in January or September, booked 18 days in advance, depart on a Wednesday or Saturday and return on a Wednesday

Cheap 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 October 28, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$289
(Southwest)

One-way from

$117
(Frontier)

Popular in

July

Cheapest in

January

Average price

$427
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
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One-way flight from Ontario to Milwaukee-Mitchell
Search Deals
Highest demand for flights based on searches. 7% potential increase in price ($34 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($8 potential savings vs. average RT price).
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Average for round-trip flights in October 2025
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Find 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 October 28, 2025.

This Frontier deal was found by Cheapflights users on 10/26. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/36:53 amONT - MKE
1 stop10h 26mFrontier
Mon 11/108:04 pmMKE - ONT
1 stop5h 46mFrontier
Deal found 10/26$253
This Southwest deal was found by Cheapflights users on 10/27. 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.
Thu 12/2512:45 pmONT - MKE
1 stop5h 50mSouthwest
Thu 1/15:05 amMKE - ONT
1 stop6h 35mSouthwest
Deal found 10/27$289
This United Airlines deal was found by Cheapflights users on 10/27. 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 12/255:05 amONT - MKE
2 stops12h 50mUnited Airlines
Thu 1/15:42 pmMKE - ONT
1 stop6h 43mUnited Airlines
Deal found 10/27$320
This Frontier deal was found by Cheapflights users on 10/26. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/276:53 amONT - MKE
1 stop10h 25mFrontier
Mon 11/38:04 pmMKE - ONT
1 stop5h 46mFrontier
Deal found 10/26$322
This American Airlines deal was found by Cheapflights users on 10/27. 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.
Wed 11/264:47 pmONT - MKE
1 stop5h 56mAmerican Airlines
Wed 12/38:53 amMKE - ONT
2 stops9h 09mAmerican Airlines
Deal found 10/27$349
This Frontier deal was found by Cheapflights users on 10/26. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/276:53 amONT - MKE
1 stop10h 25mFrontier
Fri 10/318:04 pmMKE - ONT
1 stop5h 46mFrontier
Deal found 10/26$369
This Expedia deal was found by Cheapflights users on 10/27. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/106:53 amONT - MKE
1 stop10h 26mMultiple Airlines
Thu 11/133:56 pmMKE - ONT
1 stop9h 36mMultiple Airlines
Deal found 10/27$390
This American Airlines deal was found by Cheapflights users on 10/28. 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 11/276:11 amONT - MKE
1 stop6h 13mAmerican Airlines
Mon 12/15:50 pmMKE - ONT
1 stop6h 09mAmerican Airlines
Deal found 10/28$393
This Southwest deal was found by Cheapflights users on 10/26. 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.
Thu 12/182:20 pmONT - MKE
1 stop7h 50mSouthwest
Sun 12/216:00 amMKE - ONT
1 stop6h 40mSouthwest
Deal found 10/26$394
This United Airlines deal was found by Cheapflights users on 10/27. 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 12/21:34 pmONT - MKE
1 stop5h 56mUnited Airlines
Fri 12/54:05 pmMKE - ONT
1 stop7h 44mUnited Airlines
Deal found 10/27$395

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 October 28, 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 12/25

12:45 pm-8:35 pm

1 stop5h 50m

Milwaukee-Mitchell

Thu 1/1

5:05 am-9:40 am

1 stop6h 35m

$289

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Thu 12/25

5:05 am-7:55 pm

2 stops12h 50m

Milwaukee-Mitchell

Thu 1/1

5:42 pm-10:25 pm

1 stop6h 43m

$320

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Wed 11/26

9:59 am-11:03 pm

2 stops11h 04m

Milwaukee-Mitchell

Wed 12/3

8:06 am-4:02 pm

2 stops9h 56m

$385

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Mon 11/10

6:53 am-7:19 pm

1 stop10h 26m

Milwaukee-Mitchell

Thu 11/13

3:56 pm-11:32 pm

1 stop9h 36m

$390

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Thu 11/27

6:11 am-2:24 pm

1 stop6h 13m

Milwaukee-Mitchell

Mon 12/1

5:50 pm-9:59 pm

1 stop6h 09m

$393

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Tue 12/2

1:34 pm-9:30 pm

1 stop5h 56m

Milwaukee-Mitchell

Fri 12/5

4:05 pm-9:49 pm

1 stop7h 44m

$395

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Thu 12/18

1:05 pm-11:40 pm

2 stops8h 35m

Milwaukee-Mitchell

Sun 12/21

4:45 pm-11:10 pm

2 stops8h 25m

$404

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Tue 12/2

9:59 am-9:31 pm

2 stops9h 32m

Milwaukee-Mitchell

Fri 12/5

8:53 am-4:02 pm

2 stops9h 09m

$405

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Sat 12/20

12:55 pm-9:41 pm

1 stop6h 46m

Milwaukee-Mitchell

Fri 1/2

6:14 am-11:53 am

1 stop7h 39m

$412

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Thu 2/26

1:00 pm-9:27 pm

1 stop6h 27m

Milwaukee-Mitchell

Sun 3/1

5:45 am-11:38 am

1 stop7h 53m

$423

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/27

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 October.
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

How far ahead should I book a flight from Ontario to Milwaukee?

Use this chart to determine the optimal time to book a round-trip flight from Ontario to Milwaukee. Price data was last updated on October 24, 2025.

The best time to book flights from Ontario to Milwaukee is 18 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

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 November is currently the most expensive (average of $134). 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 October 28, 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 October 28, 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
8.0
Very good
4,240 reviews

Entertainment

7.5

Boarding

8.1

Crew

8.6

Food

7.0

Comfort

8.0

Overall

8.0

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Southwest
8.0
Very good
4,240 reviews
Southwest
8.0
Very good
4,240 reviews

Entertainment

7.5

Boarding

8.1

Crew

8.6

Food

7.0

Comfort

8.0

Overall

8.0

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Delta
7.9
Good
7,994 reviews
Southwest
8.0
Very good
4,240 reviews

Entertainment

7.5

Boarding

8.1

Crew

8.6

Food

7.0

Comfort

8.0

Overall

8.0

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
United Airlines
7.4
Good
9,001 reviews
Southwest
8.0
Very good
4,240 reviews

Entertainment

7.5

Boarding

8.1

Crew

8.6

Food

7.0

Comfort

8.0

Overall

8.0

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
American Airlines
7.2
Good
11,032 reviews
Southwest
8.0
Very good
4,240 reviews

Entertainment

7.5

Boarding

8.1

Crew

8.6

Food

7.0

Comfort

8.0

Overall

8.0

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.

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 5h 50m. Southwest provides one of the quickest options available for as low as $289. 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 37% below the average price you’ll pay for this route.

  • 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 November is currently the most expensive (average of $134). 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 October 28, 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$429FlexibilityNo cancel feeOn-time63%

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