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Milwaukee

$115+ 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 3/9. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — MKE
Feb 26 — Mar 51
Thu 2/26
Thu 3/5
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 January 27, 2026.

This CheapOair deal was found by Cheapflights users on 1/27. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/52:08 pm
ONT
-
MKE
1 stop26h 43m
Frontier
Mon 3/97:46 pm
MKE
-
ONT
1 stop6h 13m
Frontier
Deal found 1/27$229
This CheapOair deal was found by Cheapflights users on 1/24. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/1912:59 am
ONT
-
MKE
1 stop16h 00m
Frontier
Fri 4/247:37 pm
MKE
-
ONT
1 stop6h 18m
Frontier
Deal found 1/24$246
This Frontier deal was found by Cheapflights users on 1/25. 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.
Fri 3/66:15 am
ONT
-
MKE
1 stop10h 36m
Frontier
Mon 3/97:46 pm
MKE
-
ONT
1 stop6h 13m
Frontier
Deal found 1/25$268
This CheapOair deal was found by Cheapflights users on 1/26. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/305:33 pm
ONT
-
MKE
1 stop23h 26m
Frontier
Mon 5/47:37 pm
MKE
-
ONT
1 stop6h 18m
Frontier
Deal found 1/26$272
This Orbitz deal was found by Cheapflights users on 1/27. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/106:14 am
ONT
-
MKE
1 stop30h 37m
Multiple Airlines
Mon 3/167:15 pm
MKE
-
ONT
1 stop6h 44m
Multiple Airlines
Deal found 1/27$303
This United Airlines deal was found by Cheapflights users on 1/27. 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 3/106:15 am
ONT
-
MKE
2 stops13h 12m
United Airlines
Mon 3/164:10 pm
MKE
-
ONT
1 stop6h 40m
United Airlines
Deal found 1/27$319
This American Airlines deal was found by Cheapflights users on 1/27. 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.
Tue 2/249:53 am
ONT
-
MKE
2 stops11h 04m
American Airlines
Sat 2/283:11 pm
MKE
-
ONT
1 stop9h 38m
American Airlines
Deal found 1/27$321
This American Airlines deal was found by Cheapflights users on 1/25. 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 2/186:15 am
ONT
-
MKE
1 stop5h 43m
American Airlines
Sat 2/217:16 am
MKE
-
ONT
1 stop11h 06m
American Airlines
Deal found 1/25$326
This Alaska Airlines deal was found by Cheapflights users on 1/25. 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 4/87:08 pm
ONT
-
MKE
1 stop17h 06m
Alaska Airlines
Tue 4/143:10 pm
MKE
-
ONT
1 stop20h 29m
Alaska Airlines
Deal found 1/25$333
This Southwest deal was found by Cheapflights users on 1/27. 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.
Tue 2/246:30 am
ONT
-
MKE
1 stop5h 30m
Southwest
Tue 2/244:50 pm
MKE
-
ONT
1 stop6h 15m
Southwest
Deal found 1/27$337
This Delta deal was found by Cheapflights users on 1/26. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 2/1510:20 pm
ONT
-
MKE
1 stop8h 49m
Delta
Tue 2/245:25 am
MKE
-
ONT
1 stop8h 37m
Delta
Deal found 1/26$338

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 January 27, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$229
(CheapOair)

One-way from

$115
(Frontier)

Popular in

January

Cheapest in

September

Average price

$846
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. 18% potential increase in price ($102 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 January 2026
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 January 27, 2026.
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 3/5

2:08 pm-6:51 pm

1 stop26h 43m

Milwaukee-Mitchell

Mon 3/9

7:46 pm-11:59 pm

1 stop6h 13m

$229

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Thu 4/30

5:33 pm-6:59 pm

1 stop23h 26m

Milwaukee-Mitchell

Mon 5/4

7:37 pm-11:55 pm

1 stop6h 18m

$272

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Tue 3/10

6:14 am-2:51 pm

1 stop30h 37m

Milwaukee-Mitchell

Mon 3/16

7:15 pm-11:59 pm

1 stop6h 44m

$303

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Tue 3/10

6:15 am-9:27 pm

2 stops13h 12m

Milwaukee-Mitchell

Mon 3/16

4:10 pm-8:50 pm

1 stop6h 40m

$319

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Tue 2/24

6:30 am-2:00 pm

1 stop5h 30m

Milwaukee-Mitchell

Tue 2/24

4:50 pm-9:05 pm

1 stop6h 15m

$337

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Tue 2/24

5:00 am-2:57 pm

1 stop7h 57m

Milwaukee-Mitchell

Sat 2/28

4:10 pm-8:50 pm

1 stop6h 40m

$337

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Sun 2/15

10:20 pm-9:09 am

1 stop8h 49m

Milwaukee-Mitchell

Tue 2/24

5:25 am-12:02 pm

1 stop8h 37m

$338

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Sun 2/15

6:15 am-1:58 pm

1 stop5h 43m

Milwaukee-Mitchell

Tue 2/24

12:26 pm-7:09 pm

2 stops8h 43m

$343

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Wed 2/11

1:24 pm-9:21 pm

1 stop5h 57m

Milwaukee-Mitchell

Thu 2/19

2:40 pm-10:57 pm

2 stops10h 17m

$343

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Thu 2/26

12:02 pm-2:51 pm

1 stop24h 49m

Milwaukee-Mitchell

Mon 3/2

3:47 pm-11:08 am

1 stop21h 21m

$353

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/25

Showing 1-10 of 21 results
1
2
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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 January.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice 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 FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-Milwaukee flight deals on Cheapflights vs. FlightHub >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 FlightHub the most. FlightHub 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 January 23, 2026.

The best time to book flights from Ontario to Milwaukee is 50 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 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.

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 January 27, 2026.
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
4,268 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Overall

8.0

Crew

8.6

Food

7.0

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
8.0
Very good
4,268 reviews
Southwest
8.0
Very good
4,268 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Overall

8.0

Crew

8.6

Food

7.0

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
8,118 reviews
Southwest
8.0
Very good
4,268 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Overall

8.0

Crew

8.6

Food

7.0

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
9,205 reviews
Southwest
8.0
Very good
4,268 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Overall

8.0

Crew

8.6

Food

7.0

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
11,197 reviews
Southwest
8.0
Very good
4,268 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Overall

8.0

Crew

8.6

Food

7.0

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 5h 30m. Frontier provides one of the quickest options available for as low as $337. 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 $122. 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

Browse thousands of different options on Cheapflights for your next trip

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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 January 27, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$253Average$391FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$276Average$404FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$309Average$426FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$330Average$418FlexibilityNo cancel feeOn-time63%

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