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$143+ 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 6/30. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — MKE
jun. 17 — jun. 241
mar. 6/17
mar. 6/24
1 adult, Economy
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Cheapflights Tip: The best prices from Ontario to Milwaukee-Mitchell are usually found in November or January, booked 51 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 junio 12, 2025.

Round-trip from

$238
(CheapOair)

One-way from

$143
(Trip.com)

Popular in

July

Cheapest in

November

Average price

$416
From Ontario to Milwaukee-Mitchell
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One-way flight from Ontario to Milwaukee-Mitchell
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Highest demand for flights based on searches. 6% potential increase in price ($26 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($8 potential savings vs. average RT price).
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Average for round-trip flights in June 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 junio 12, 2025.

This CheapOair deal was found by Cheapflights users on 6/9. 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.
dom. 8/1712:59 amONT - MKE
1 stop16h 14mFrontier
vie. 8/228:02 pmMKE - ONT
1 stop5h 48mFrontier
Deal found 6/9$238
This Hawaiian Airlines deal was found by Cheapflights users on 6/10. 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 Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 8/2611:39 amONT - MKE
1 stop10h 20mHawaiian Airlines
mar. 9/96:30 amMKE - ONT
1 stop9h 39mHawaiian Airlines
Deal found 6/10$296
This American Airlines deal was found by Cheapflights users on 6/12. 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.
lun. 8/1811:59 pmONT - MKE
1 stop8h 31mAmerican Airlines
jue. 8/216:16 amMKE - ONT
1 stop9h 25mAmerican Airlines
Deal found 6/12$297
This Delta deal was found by Cheapflights users on 6/9. 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.
jue. 8/2811:45 amONT - MKE
1 stop9h 51mDelta
sáb. 8/3011:47 amMKE - ONT
1 stop9h 24mDelta
Deal found 6/9$306
This Southwest deal was found by Cheapflights users on 6/11. 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.
jue. 9/43:30 pmONT - MKE
1 stop5h 30mSouthwest
lun. 9/87:55 amMKE - ONT
2 stops14h 00mSouthwest
Deal found 6/11$308
This Trip.com deal was found by Cheapflights users on 6/12. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 6/206:00 amONT - MKE
1 stop12h 25mMultiple Airlines
lun. 6/239:20 pmMKE - ONT
1 stop26h 31mMultiple Airlines
Deal found 6/12$360
This Alaska Airlines deal was found by Cheapflights users on 6/10. 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.
mar. 8/267:10 amONT - MKE
2 stops14h 49mAlaska Airlines
mar. 9/96:30 amMKE - ONT
1 stop9h 39mAlaska Airlines
Deal found 6/10$365
This United Airlines deal was found by Cheapflights users on 6/12. 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.
mar. 10/216:00 amONT - MKE
1 stop9h 08mUnited Airlines
jue. 10/2310:55 amMKE - ONT
1 stop8h 28mUnited Airlines
Deal found 6/12$387

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 junio 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

dom. 8/17

12:59 am-7:13 pm

1 stop16h 14m

Milwaukee-Mitchell

vie. 8/22

8:02 pm-11:50 pm

1 stop5h 48m

$238

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

mar. 8/26

11:39 am-11:59 pm

1 stop10h 20m

Milwaukee-Mitchell

mar. 9/9

6:30 am-2:09 pm

1 stop9h 39m

$296

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

lun. 8/18

11:59 pm-10:30 am

1 stop8h 31m

Milwaukee-Mitchell

jue. 8/21

6:16 am-1:41 pm

1 stop9h 25m

$297

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

jue. 8/28

11:45 am-11:36 pm

1 stop9h 51m

Milwaukee-Mitchell

sáb. 8/30

11:47 am-7:11 pm

1 stop9h 24m

$306

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

jue. 9/4

3:30 pm-11:00 pm

1 stop5h 30m

Milwaukee-Mitchell

lun. 9/8

7:55 am-7:55 pm

2 stops14h 00m

$308

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

mar. 8/19

6:58 pm-11:59 pm

1 stop27h 01m

Milwaukee-Mitchell

jue. 8/21

6:30 am-2:09 pm

1 stop9h 39m

$360

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

mar. 10/21

6:00 am-5:08 pm

1 stop9h 08m

Milwaukee-Mitchell

jue. 10/23

10:55 am-5:23 pm

1 stop8h 28m

$387

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

mar. 6/24

7:00 am-8:25 pm

1 stop11h 25m

Milwaukee-Mitchell

vie. 6/27

7:56 pm-9:01 am

1 stop15h 05m

$485

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

lun. 6/30

6:00 am-8:25 pm

1 stop12h 25m

$143

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

mié. 9/10

11:39 am-11:59 pm

1 stop10h 20m

$148

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/11

Showing 1-10 of 16 results
1
2

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 June 9, 2025.

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, February is the cheapest month in which you can book a flight from Ontario to Milwaukee (average of $280). Flying from Ontario to Milwaukee in June is currently the most expensive (average of $376). 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 junio 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 33% on airfare.

Rainfall in Milwaukee by month

Plan your trip to Milwaukee by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Milwaukee ranges from 1.4 - 4.0 inches per month. June is typically the wettest month, when rainfall can reach 4.0 in. January is typically the driest time to visit Milwaukee when rainfall is around 1.4 in.

Temperature in Milwaukee by month

Plan your trip to Milwaukee by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Milwaukee, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 73.4 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 21.2 F).

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 junio 12, 2025.
See what other customers who have flown with Alaska Airlines, Southwest and Delta from Ontario to Milwaukee have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Southwest
8.0
Very good
4,287 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Delta
8.0
Very good
7,946 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Hawaiian Airlines
7.9
Good
2,494 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
United Airlines
7.4
Good
8,790 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

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.

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

    Frontier, at $238, was found to be the cheapest airline from Ontario to Milwaukee.Alternate airlines to your destination round-trip include Hawaiian Airlines and American Airlines. Frontier is currently priced 41% 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 Alaska Airlines. According to our data, you can fly for as low as $148. Users have also found prices from $149 and $179 on Delta and Frontier, 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, February is the cheapest month in which you can book a flight from Ontario to Milwaukee (average of $280). Flying from Ontario to Milwaukee in June is currently the most expensive (average of $376). 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 Ontario?

Book flights to Ontario if you plan to visit one of these locations
Mequon
Sheboygan
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 5 airlines flying from Ontario to Milwaukee

Discover the top 5 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 junio 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$140Average$249FlexibilityNo cancel feeOn-time62%
DeltaCheapest$253Average$367FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$306Average$403FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$326Average$416FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$391Average$514FlexibilityNo cancel feeOn-time69%

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