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$65+ 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 11/10. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — MKE
Oct 11 — Oct 181
Sat 10/11
Sat 10/18
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 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 September 11, 2025.

Round-trip from

$196
(Frontier)

One-way from

$65
(Trip.com)

Popular in

July

Cheapest in

November

Average price

$397
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. 8% potential increase in price ($38 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 September 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 September 11, 2025.

This Frontier deal was found by Cheapflights users on 9/9. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/136:53 amONT - MKE
1 stop10h 25mFrontier
Fri 10/178:04 pmMKE - ONT
1 stop5h 46mFrontier
Deal found 9/9$196
This Kiwi.com deal was found by Cheapflights users on 9/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/316:53 amONT - MKE
1 stop10h 26mFrontier
Mon 11/38:04 pmMKE - ONT
1 stop29h 46mFrontier
Deal found 9/9$199
This Frontier deal was found by Cheapflights users on 9/8. 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.
Thu 10/3010:40 pmONT - MKE
2 stops18h 39mFrontier
Mon 11/38:04 pmMKE - ONT
1 stop5h 46mFrontier
Deal found 9/8$225
This Kiwi.com deal was found by Cheapflights users on 9/10. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/246:05 amONT - MKE
1 stop10h 38mMultiple Airlines
Mon 10/278:04 pmMKE - ONT
1 stop29h 46mMultiple Airlines
Deal found 9/10$241
This United Airlines deal was found by Cheapflights users on 9/10. 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 10/81:15 pmONT - MKE
1 stop5h 53mUnited Airlines
Wed 10/155:45 pmMKE - ONT
1 stop6h 45mUnited Airlines
Deal found 9/10$243
This Frontier deal was found by Cheapflights users on 9/10. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/206:53 amONT - MKE
1 stop10h 25mFrontier
Fri 10/248:04 pmMKE - ONT
1 stop5h 46mFrontier
Deal found 9/10$253
This United Airlines deal was found by Cheapflights users on 9/10. 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.
Fri 10/101:15 pmONT - MKE
1 stop5h 53mUnited Airlines
Wed 10/155:45 pmMKE - ONT
1 stop6h 45mUnited Airlines
Deal found 9/10$269
This Delta deal was found by Cheapflights users on 9/10. 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 10/41:15 pmONT - MKE
1 stop6h 07mDelta
Tue 10/72:04 pmMKE - ONT
1 stop7h 15mDelta
Deal found 9/10$277
This Delta deal was found by Cheapflights users on 9/10. 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 10/217:05 amONT - MKE
1 stop7h 13mDelta
Fri 10/242:04 pmMKE - ONT
1 stop7h 15mDelta
Deal found 9/10$286

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 September 11, 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

Fri 10/10

1:15 pm-9:08 pm

1 stop5h 53m

Milwaukee-Mitchell

Wed 10/15

5:45 pm-10:30 pm

1 stop6h 45m

$269

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Sat 10/4

1:15 pm-9:22 pm

1 stop6h 07m

Milwaukee-Mitchell

Tue 10/7

2:04 pm-7:19 pm

1 stop7h 15m

$277

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Wed 10/8

1:15 pm-9:08 pm

1 stop5h 53m

Milwaukee-Mitchell

Wed 10/15

10:50 am-5:23 pm

2 stops8h 33m

$289

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Fri 10/3

10:00 pm-9:24 am

1 stop9h 24m

Milwaukee-Mitchell

Sun 10/5

5:40 am-10:42 am

1 stop7h 02m

$346

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Fri 10/10

1:15 pm-9:08 pm

1 stop5h 53m

Milwaukee-Mitchell

Tue 10/14

5:45 pm-10:30 pm

1 stop6h 45m

$359

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Wed 11/5

7:00 am-5:17 pm

1 stop8h 17m

Milwaukee-Mitchell

Sun 11/9

8:15 am-12:33 pm

1 stop6h 18m

$374

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Fri 12/19

5:05 am-3:00 pm

1 stop7h 55m

Milwaukee-Mitchell

Thu 1/1

4:11 pm-9:07 pm

1 stop6h 56m

$379

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Tue 10/21

1:15 pm-9:08 pm

1 stop5h 53m

Milwaukee-Mitchell

Thu 10/23

5:00 am-12:13 pm

2 stops9h 13m

$379

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Thu 11/6

7:00 am-5:17 pm

1 stop8h 17m

Milwaukee-Mitchell

Thu 11/13

2:30 pm-8:44 pm

1 stop8h 14m

$389

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Thu 10/9

5:05 am-1:01 pm

1 stop5h 56m

Milwaukee-Mitchell

Tue 10/14

5:00 am-12:51 pm

2 stops9h 51m

$394

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/11

Showing 1-10 of 23 results
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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 August 29, 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, 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 September 11, 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.

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 September 11, 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
4,248 reviews

Boarding

8.1

Overall

8.0

Entertainment

7.5

Food

7.0

Crew

8.6

Comfort

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
4,248 reviews
Southwest
8.0
Very good
4,248 reviews

Boarding

8.1

Overall

8.0

Entertainment

7.5

Food

7.0

Crew

8.6

Comfort

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
8.0
Very good
7,960 reviews
Southwest
8.0
Very good
4,248 reviews

Boarding

8.1

Overall

8.0

Entertainment

7.5

Food

7.0

Crew

8.6

Comfort

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
8,937 reviews
Southwest
8.0
Very good
4,248 reviews

Boarding

8.1

Overall

8.0

Entertainment

7.5

Food

7.0

Crew

8.6

Comfort

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
10,000 reviews
Southwest
8.0
Very good
4,248 reviews

Boarding

8.1

Overall

8.0

Entertainment

7.5

Food

7.0

Crew

8.6

Comfort

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 53m. United Airlines provides one of the quickest options available for as low as $269. 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 Southwest. 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, 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 Milwaukee?

Book flights to Milwaukee if you plan to visit one of these locations
Sheboygan
Oak Creek
New Berlin
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 September 11, 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$253Average$391FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$276Average$398FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$326Average$417FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$366Average$472FlexibilityNo cancel feeOn-time69%

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