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$138+ Cheap flights from Milwaukee to Ontario (MKE - ONT)

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.
MKE — ONT
Oct 15 — Oct 221
Wed 10/15
Wed 10/22
1 adult, Economy
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Cheap flight deals from Milwaukee to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from Milwaukee (MKE) to Ontario (ONT). 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 15, 2025.

Round-trip from

$196
(Frontier)

One-way from

$138
(Alaska Airlines)

Popular in

September

Cheapest in

August

Average price

$758
From Milwaukee-Mitchell to Ontario
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One-way flight from Milwaukee-Mitchell to Ontario
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Highest demand for flights based on searches. 17% potential increase in price ($92 potential increase over avg. RT price).
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Cheapest flight prices on average. 6% potential price decrease ($29 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 Milwaukee to Ontario

Cheapest flights from Milwaukee to Ontario
Explore the most affordable flight options available from Milwaukee to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 15, 2025.

This Frontier deal was found by Cheapflights users on 9/13. 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 10/178:04 pmMKE - ONT
1 stop5h 46mFrontier
Mon 10/206:53 amONT - MKE
1 stop10h 25mFrontier
Deal found 9/13$196
This Frontier deal was found by Cheapflights users on 9/12. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/78:04 pmMKE - ONT
1 stop5h 46mFrontier
Mon 11/106:53 amONT - MKE
1 stop10h 26mFrontier
Deal found 9/12$215
This American Airlines deal was found by Cheapflights users on 9/12. 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.
Wed 10/297:00 amMKE - ONT
1 stop7h 01mAmerican Airlines
Wed 11/56:10 amONT - MKE
1 stop8h 54mAmerican Airlines
Deal found 9/12$243
This Delta deal was found by Cheapflights users on 9/12. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/247:30 amMKE - ONT
1 stop6h 48mDelta
Wed 12/31:20 pmONT - MKE
1 stop6h 29mDelta
Deal found 9/12$277
This Frontier deal was found by Cheapflights users on 9/11. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/108:04 pmMKE - ONT
1 stop5h 46mFrontier
Mon 10/136:53 amONT - MKE
1 stop10h 25mFrontier
Deal found 9/11$284
This Delta deal was found by Cheapflights users on 9/12. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/12:59 pmMKE - ONT
1 stop9h 24mDelta
Fri 10/310:00 pmONT - MKE
1 stop9h 24mDelta
Deal found 9/12$286
This Delta deal was found by Cheapflights users on 9/12. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/297:30 amMKE - ONT
2 stops11h 40mDelta
Wed 11/510:00 pmONT - MKE
2 stops12h 25mDelta
Deal found 9/12$287
This Frontier deal was found by Cheapflights users on 9/13. 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 10/108:04 pmMKE - ONT
1 stop5h 46mFrontier
Sun 10/1210:40 pmONT - MKE
2 stops18h 38mFrontier
Deal found 9/13$291
This American Airlines deal was found by Cheapflights users on 9/12. 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.
Sun 11/233:09 pmMKE - ONT
1 stop9h 14mAmerican Airlines
Thu 11/276:11 amONT - MKE
1 stop6h 13mAmerican Airlines
Deal found 9/12$301
This American Airlines deal was found by Cheapflights users on 9/12. 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.
Thu 10/92:05 pmMKE - ONT
1 stop8h 02mAmerican Airlines
Sat 10/114:49 pmONT - MKE
1 stop5h 31mAmerican Airlines
Deal found 9/12$317

Cheapflights Fare Finder

 
Customize your flight search to find flights from Milwaukee to Ontario 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 15, 2025.
Use the filters below to find and compare flights from Milwaukee to Ontario that are best for you.

Fly from

Milwaukee

Fly to

Ontario

Route

Depart

Return

Price

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Sat 12/6

3:17 pm-10:04 pm

1 stop8h 47m

Ontario

Tue 12/9

1:20 pm-9:49 pm

1 stop6h 29m

$277

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Wed 10/29

10:35 am-9:20 pm

2 stops12h 45m

Ontario

Wed 11/5

10:00 pm-9:26 am

1 stop9h 26m

$282

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Fri 10/10

8:04 pm-11:50 pm

1 stop5h 46m

Ontario

Mon 10/13

6:53 am-7:18 pm

1 stop10h 25m

$284

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Wed 10/29

7:00 am-3:24 pm

1 stop10h 24m

Ontario

Wed 11/5

6:20 am-2:24 pm

1 stop6h 04m

$312

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Wed 12/10

3:17 pm-11:03 pm

1 stop9h 46m

Ontario

Tue 12/16

10:25 pm-9:30 am

1 stop9h 05m

$317

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Sat 10/18

6:13 am-1:43 pm

1 stop9h 30m

Ontario

Tue 10/21

6:15 am-12:20 am

1 stop16h 05m

$322

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Sat 10/18

6:13 am-1:43 pm

1 stop9h 30m

Ontario

Mon 10/20

11:59 pm-10:43 am

1 stop8h 44m

$337

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Sat 10/18

1:10 pm-9:20 pm

2 stops10h 10m

Ontario

Mon 10/20

10:00 pm-12:25 pm

2 stops12h 25m

$347

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Tue 11/25

7:30 am-12:18 pm

1 stop6h 48m

Ontario

Wed 12/3

1:20 pm-9:49 pm

1 stop6h 29m

$357

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Mon 10/13

7:38 pm-8:42 pm

1 stop27h 04m

$148

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/12

Showing 1-10 of 20 results
1
2

Best time to book a flight from Milwaukee to Ontario

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

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

Currently, August is the cheapest month in which you can book a flight from Milwaukee to Ontario (average of $246). Flying from Milwaukee to Ontario in March is currently the most expensive (average of $328). 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 MKE to ONT?

Find hourly flight availability from Milwaukee to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 15, 2025.

It’s typically best to fly out from Milwaukee to Ontario in the evening. Doing so could potentially save you 30% on the flight price compared to flying at noon, which is usually more expensive.

What is the cheapest day to fly from Milwaukee to Ontario?

Use this chart to determine the cheapest time to fly round-trip from Milwaukee to Ontario. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Milwaukee to Ontario flight should consider departing on Monday mornings when fares are most often at their lowest. Friday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated September 15, 2025.
Read through reviews of airlines operating flights from Milwaukee to Ontario, such as Southwest, Delta, and United Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,245 reviews

Comfort

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Overall

8.0

Entertainment

7.5

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
4,245 reviews
Southwest
8.0
Very good
4,245 reviews

Comfort

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Overall

8.0

Entertainment

7.5

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
7,956 reviews
Southwest
8.0
Very good
4,245 reviews

Comfort

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Overall

8.0

Entertainment

7.5

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
8,931 reviews
Southwest
8.0
Very good
4,245 reviews

Comfort

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Overall

8.0

Entertainment

7.5

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
4,245 reviews

Comfort

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Overall

8.0

Entertainment

7.5

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 Milwaukee to Ontario. 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 Milwaukee to Ontario?

    For as low as $284, Delta can have you in Ontario from Milwaukee in 5h 46m. There are 1707 mi between Milwaukee and Ontario. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

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

    Our cheapest airline available from Milwaukee to Ontario is American Airlines. Our recent data shows that you can find tickets from as low as $291 on this airline. Additional options worth looking into are Southwest and Delta, starting at $336 and $336 round-trip. American Airlines is priced at 34% lower than the current average price of a flight leaving 3 months from now.

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

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

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

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

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

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

    Currently, August is the cheapest month in which you can book a flight from Milwaukee to Ontario (average of $246). Flying from Milwaukee to Ontario in March is currently the most expensive (average of $328). 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

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Top 4 airlines flying from Milwaukee to Ontario

Discover the top 4 airlines that operate flights from Milwaukee to Ontario. 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 15, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$291Average$381FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$336Average$420FlexibilityNo cancel feeOn-time63%
DeltaCheapest$336Average$402FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$344Average$434FlexibilityNo cancel feeOn-time69%

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