HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Ontario

$109+ 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 3/9. Fares are subject to change and may not be available on all flights or dates of travel.
MKE — ONT
Feb 28 — Mar 71
Sat 2/28
Sat 3/7
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Milwaukee to Ontario with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap 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 January 29, 2026.

This Expedia 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/237:15 pm
MKE
-
ONT
1 stop6h 44m
Frontier
Mon 3/309:49 pm
ONT
-
MKE
1 stop13h 13m
Frontier
Deal found 1/26$238
This United Airlines deal was found by Cheapflights users on 1/28. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 2/214:10 pm
MKE
-
ONT
1 stop6h 40m
United Airlines
Tue 2/245:00 am
ONT
-
MKE
1 stop7h 57m
United Airlines
Deal found 1/28$257
This Expedia 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/67:46 pm
MKE
-
ONT
1 stop6h 13m
Frontier
Mon 3/96:15 am
ONT
-
MKE
1 stop10h 36m
Frontier
Deal found 1/27$268
This Delta deal was found by Cheapflights users on 1/28. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/247:30 am
MKE
-
ONT
1 stop6h 37m
Delta
Tue 3/31:15 pm
ONT
-
MKE
1 stop8h 32m
Delta
Deal found 1/28$277
This Delta 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/197:30 am
MKE
-
ONT
1 stop6h 37m
Delta
Sat 2/2810:20 pm
ONT
-
MKE
1 stop8h 49m
Delta
Deal found 1/27$307
This Delta deal was found by Cheapflights users on 1/28. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/2712:20 pm
MKE
-
ONT
1 stop10h 45m
Delta
Wed 3/41:10 pm
ONT
-
MKE
1 stop6h 22m
Delta
Deal found 1/28$308
This Frontier deal was found by Cheapflights users on 1/28. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/167:15 pm
MKE
-
ONT
1 stop6h 44m
Frontier
Fri 3/206:15 am
ONT
-
MKE
1 stop10h 36m
Frontier
Deal found 1/28$309
This Expedia 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/53:47 pm
MKE
-
ONT
1 stop9h 45m
Multiple Airlines
Mon 3/96:15 am
ONT
-
MKE
1 stop10h 36m
Multiple Airlines
Deal found 1/27$314
This Delta deal was found by Cheapflights users on 1/28. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/247:30 am
MKE
-
ONT
1 stop6h 37m
Delta
Tue 3/106:00 am
ONT
-
MKE
2 stops13h 15m
Delta
Deal found 1/28$320

Find 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 January 29, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$238
(Expedia)

One-way from

$109
(Frontier)

Popular in

February

Cheapest in

January

Average price

$306
Provider with most accurate pricing for Milwaukee-Mitchell-Ontario flight deals.
Search Deals
Provider most trusted by Cheapflights users for Milwaukee-Mitchell-Ontario flights.
Search Deals
From Milwaukee-Mitchell to Ontario
Search Deals
One-way flight from Milwaukee-Mitchell to Ontario
Search Deals
Highest demand for flights based on searches. 0% potential increase in price ($3 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($11 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 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 January 29, 2026.
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 4/25

3:52 pm-9:50 pm

1 stop7h 58m

Ontario

Wed 5/6

5:00 am-1:31 pm

1 stop6h 31m

$257

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Sat 2/21

9:44 am-8:50 pm

2 stops13h 06m

Ontario

Tue 2/24

5:00 am-2:57 pm

1 stop7h 57m

$262

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Wed 2/25

5:00 am-12:43 pm

2 stops9h 43m

Ontario

Wed 3/11

5:15 am-2:58 pm

1 stop7h 43m

$262

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Sat 4/11

7:35 am-12:23 pm

1 stop6h 48m

Ontario

Tue 4/21

12:49 pm-11:57 pm

1 stop9h 08m

$277

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Wed 3/11

5:45 am-11:47 am

1 stop8h 02m

Ontario

Wed 3/18

1:20 pm-9:15 pm

1 stop5h 55m

$277

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Sat 2/28

7:30 am-12:07 pm

1 stop6h 37m

Ontario

Wed 3/4

10:20 pm-9:09 am

1 stop8h 49m

$277

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Sat 2/28

7:30 am-12:07 pm

1 stop6h 37m

Ontario

Sat 2/28

10:20 pm-9:09 am

1 stop8h 49m

$277

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Tue 2/24

7:30 am-12:07 pm

1 stop6h 37m

Ontario

Mon 3/9

10:25 pm-9:04 am

1 stop8h 39m

$324

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Wed 3/11

7:35 am-12:23 pm

1 stop6h 48m

Ontario

Tue 3/24

1:20 pm-9:15 pm

1 stop5h 55m

$328

MilwaukeeOntario

MKE - ONT

MKEONT

Milwaukee-Mitchell

Sat 4/25

7:00 am-2:32 pm

1 stop9h 32m

Ontario

Mon 5/4

7:00 am-2:13 pm

2 stops29h 13m

$335

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/28

Showing 1-10 of 23 results
1
2
3

Compare providers for flights from Milwaukee to Ontario

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 Milwaukee to Ontario in January.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
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 Milwaukee-Ontario flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Milwaukee-Ontario flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Milwaukee-Ontario flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Milwaukee-Ontario 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 Milwaukee-Ontario 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 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, September is the cheapest month in which you can book a flight from Milwaukee to Ontario (average of $80). Flying from Milwaukee to Ontario in January 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.

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 January 29, 2026.
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
4,267 reviews

Crew

8.6

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Food

7.0

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
4,267 reviews
Southwest
8.0
Very good
4,267 reviews

Crew

8.6

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Food

7.0

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
8,128 reviews
Southwest
8.0
Very good
4,267 reviews

Crew

8.6

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Food

7.0

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
9,215 reviews
Southwest
8.0
Very good
4,267 reviews

Crew

8.6

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Food

7.0

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
11,205 reviews
Southwest
8.0
Very good
4,267 reviews

Crew

8.6

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Food

7.0

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 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 $277, United Airlines can have you in Ontario from Milwaukee in 6h 48m. 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 Delta. Our recent data shows that you can find tickets from as low as $300 on this airline. Additional options worth looking into are American Airlines and Southwest, starting at $324 and $330 round-trip. Delta is priced at 31% lower than the current average price of a flight leaving 3 months from now.

  • What are the cheapest airlines to fly from Milwaukee to Ontario one-way?

    The cheapest airlines for a one-way flight from Milwaukee to Ontario are Frontier ($129), United Airlines ($138), and Southwest ($153).

  • 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, September is the cheapest month in which you can book a flight from Milwaukee to Ontario (average of $80). Flying from Milwaukee to Ontario in January 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

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Milwaukee to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
O'Hare Intl to Las Vegas flights
Minneapolis to Las Vegas flights
O'Hare Intl to Los Angeles flights
O'Hare Intl to San Francisco flights
Minneapolis to San Diego flights
O'Hare Intl to Santa Ana flights
Minneapolis to Los Angeles flights
O'Hare Intl to San Diego flights
Milwaukee to Las Vegas flights
O'Hare Intl to Ontario flights
Minneapolis to San Francisco flights
O'Hare Intl to Palm Springs flights
Minneapolis to Palm Springs flights
O'Hare Intl to Burbank flights
Madison to Las Vegas flights
O'Hare Intl to Reno flights
Minneapolis to Ontario flights
O'Hare Intl to San Jose flights
O'Hare Intl to Sacramento flights
Minneapolis to Santa Ana flights
O'Hare Intl to Oakland flights
Appleton to Las Vegas flights
Milwaukee to Los Angeles flights
Minneapolis to Sacramento flights
Milwaukee to San Diego flights
Minneapolis to Reno flights
Minneapolis to San Jose flights
Milwaukee to San Francisco flights
Milwaukee to Palm Springs flights
Madison to San Diego flights
Madison to San Francisco flights
Madison to Los Angeles flights
Green Bay to Las Vegas flights
O'Hare Intl to Long Beach flights
Milwaukee to Reno flights
Minneapolis to Oakland flights
O'Hare Intl to Fresno flights
O'Hare Intl to Santa Barbara flights
Appleton to San Diego flights
Minneapolis to Fresno flights
Madison to Ontario flights
Minneapolis to Santa Barbara flights
Minneapolis to Burbank flights
Appleton to Los Angeles flights
Madison to Palm Springs flights
Madison to Santa Ana flights
Milwaukee to Sacramento flights
Milwaukee to San Jose flights
Minneapolis to Long Beach flights

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 January 29, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$300Average$444FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$324Average$376FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$330Average$426FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$344Average$526FlexibilityNo cancel feeOn-time69%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.