What is the cheapest airline that flies from Ontario to Milwaukee-Mitchell?

Frontier, American Airlines, and Delta are the most popular carriers operating from Ontario to Milwaukee-Mitchell

What airlines fly to Milwaukee?

American Airlines, United Airlines and Spirit Airlines are the top three most popular airlines that fly to Milwaukee from Ontario according to our data. American Airlines is the first choice among our users, with 42% of people opting to fly with this airline when traveling to Milwaukee. Keep in mind that there are 10 different airlines that fly to Milwaukee on a routine basis, so you have a few additional options to choose from.

When did momondo last update prices for flights from Ontario Airport to Milwaukee-Mitchell Airport?

Prices for flights from Ontario Airport to Milwaukee-Mitchell Airport are updated daily.

How many operators does momondo search for flights from Ontario Airport to Milwaukee-Mitchell Airport?

As of January 2026, there are 4 operators available to choose from for flights from Ontario Airport to Milwaukee-Mitchell Airport.

How old do you have to be to fly from Ontario Airport to Milwaukee-Mitchell Airport?

Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Ontario Airport to Milwaukee-Mitchell Airport.

What documentation or ID do you need to fly to Milwaukee-Mitchell Airport?

The travel and health documents required for your trip to Milwaukee-Mitchell Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Milwaukee-Mitchell Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

$115 Cheap Flights from Ontario to Milwaukee in 2026

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Find the cheapest flights from Ontario to Milwaukee

Round-trip

One-way

Last minute

Cheap round-trip flights

Enter your travel dates to find the best prices.

2:08 pm - 6:51 pm

ONT

MKE

26h 43m

1 stop

7:46 pm - 11:59 pm

MKE

ONT

6h 13m

1 stop

$229Frontier

Thu, Mar 5 - Mon, Mar 9

12:18 pm - 9:34 pm

ONT

MKE

7h 16m

1 stop

3:11 pm - 10:49 pm

MKE

ONT

9h 38m

1 stop

$257American Airlines

Wed, Feb 18 - Sat, Feb 21

12:18 pm - 10:57 pm

ONT

MKE

8h 39m

2 stops

3:11 pm - 10:49 pm

MKE

ONT

9h 38m

1 stop

$262American Airlines

Wed, Feb 18 - Sat, Feb 21

6:15 am - 6:51 pm

ONT

MKE

10h 36m

1 stop

7:46 pm - 11:59 pm

MKE

ONT

6h 13m

1 stop

$268Frontier

Fri, Mar 6 - Mon, Mar 9

5:33 pm - 6:59 pm

ONT

MKE

23h 26m

1 stop

7:37 pm - 11:55 pm

MKE

ONT

6h 18m

1 stop

$272Frontier

Thu, Apr 30 - Mon, May 4

6:14 am - 2:51 pm

ONT

MKE

30h 37m

1 stop

7:15 pm - 11:59 pm

MKE

ONT

6h 44m

1 stop

$303Multiple Airlines

Tue, Mar 10 - Mon, Mar 16

9:53 am - 10:57 pm

ONT

MKE

11h 04m

2 stops

3:11 pm - 10:49 pm

MKE

ONT

9h 38m

1 stop

$321American Airlines

Tue, Feb 24 - Sat, Feb 28

9:53 am - 10:57 pm

ONT

MKE

11h 04m

2 stops

6:22 am - 4:22 pm

MKE

ONT

12h 00m

2 stops

$326American Airlines

Tue, Feb 24 - Sat, Feb 28

7:05 pm - 7:49 am

ONT

MKE

10h 44m

2 stops

6:22 am - 4:22 pm

MKE

ONT

12h 00m

2 stops

$332American Airlines

Wed, Feb 18 - Sat, Feb 21

5:00 am - 2:57 pm

ONT

MKE

7h 57m

1 stop

4:10 pm - 8:50 pm

MKE

ONT

6h 40m

1 stop

$337United Airlines

Tue, Feb 24 - Sat, Feb 28

Frontier flights from Ontario to Milwaukee

Our best Frontier deals on Ontario to Milwaukee flight tickets

Frontier

Mar 5

ONT2:08 pmOntario

26h 43m

1 stop

MKE6:51 pmMilwaukee-Mitchell

Mar 9

MKE7:46 pmMilwaukee-Mitchell

6h 13m

1 stop

ONT11:59 pmOntario

$229

Frontier

Mar 6

ONT6:15 amOntario

10h 36m

1 stop

MKE6:51 pmMilwaukee-Mitchell

Mar 9

MKE7:46 pmMilwaukee-Mitchell

6h 13m

1 stop

ONT11:59 pmOntario

$268

Frontier

Apr 30

ONT5:33 pmOntario

23h 26m

1 stop

MKE6:59 pmMilwaukee-Mitchell

May 4

MKE7:37 pmMilwaukee-Mitchell

6h 18m

1 stop

ONT11:55 pmOntario

$272

United Airlines flights from Ontario to Milwaukee

Our best United Airlines deals on Ontario to Milwaukee flight tickets

United Airlines

Feb 24

ONT5:00 amOntario

7h 57m

1 stop

MKE2:57 pmMilwaukee-Mitchell

Feb 28

MKE4:10 pmMilwaukee-Mitchell

6h 40m

1 stop

ONT8:50 pmOntario

$337

United Airlines

Feb 11

ONT1:24 pmOntario

5h 57m

1 stop

MKE9:21 pmMilwaukee-Mitchell

Feb 19

MKE2:40 pmMilwaukee-Mitchell

10h 17m

2 stops

ONT10:57 pmOntario

$343

United Airlines

May 6

ONT5:00 amOntario

6h 31m

1 stop

MKE1:31 pmMilwaukee-Mitchell

May 9

MKE1:46 pmMilwaukee-Mitchell

6h 15m

1 stop

ONT6:01 pmOntario

$347

Fly from

Fly to

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

Wed 2/18

12:18 pm-9:34 pm

1 stop7h 16m

Milwaukee-Mitchell

Sat 2/21

3:11 pm-10:49 pm

1 stop9h 38m

$257

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Wed 2/18

12:18 pm-10:57 pm

2 stops8h 39m

Milwaukee-Mitchell

Sat 2/21

3:11 pm-10:49 pm

1 stop9h 38m

$262

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Fri 3/6

6:15 am-6:51 pm

1 stop10h 36m

Milwaukee-Mitchell

Mon 3/9

7:46 pm-11:59 pm

1 stop6h 13m

$268

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 2/24

9:53 am-10:57 pm

2 stops11h 04m

Milwaukee-Mitchell

Sat 2/28

3:11 pm-10:49 pm

1 stop9h 38m

$321

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Tue 2/24

9:53 am-10:57 pm

2 stops11h 04m

Milwaukee-Mitchell

Sat 2/28

6:22 am-4:22 pm

2 stops12h 00m

$326

OntarioMilwaukee

ONT - MKE

ONTMKE

Ontario

Wed 2/18

7:05 pm-7:49 am

2 stops10h 44m

Milwaukee-Mitchell

Sat 2/21

6:22 am-4:22 pm

2 stops12h 00m

$332

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

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

How to get the cheapest flight ticket from Ontario to Milwaukee

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

Prices

Airlines

What is the cheapest month to fly to Milwaukee?

The cheapest month to fly to Milwaukee from Ontario is in September. Flight prices, which tend to average around $366, are often lower during this time because this is during the off-season. The month of May is another great option to travel to Milwaukee, with average flight prices from Ontario averaging around $374.

What is the cheapest day to depart on your flight to Milwaukee?

According to our data, Thursday is the cheapest day to fly to Milwaukee from Ontario. The lowest ticket price found for a Thursday departure recently was $181. Keep in mind that prices can always vary depending on your route and whether or not you are flying domestic or international. Flights from Ontario to Milwaukee on a Sunday will generally be more expensive and average around $189. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

How far in advance should I book a flight to Milwaukee?

You are more likely to see cheaper flights to Milwaukee from Ontario when booking weeks ahead of your departure date. In general, you can expect to find flights to Milwaukee for around $454 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Milwaukee from Ontario for as low as $305 on momondo.

How have Ontario to Milwaukee flight prices changed over time?

As of January 2026, prices for Ontario to Milwaukee flights are approximately 78% cheaper when compared to flights at the same time last year.

When to book flights from Ontario to Milwaukee

Are you open to changing your travel dates? Check out the ideal times to fly from Ontario to Milwaukee according to our flight data. Find out which month and days have the cheapest flights.

Estimated round-trip price

Cheap Ontario to Milwaukee (ONT to MKE) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Ontario to Milwaukee

Fastest flight time	6h 22m
Direct flights	None

The fastest flight from Ontario to Milwaukee takes 6h 22m

There are no direct flights from Ontario to Milwaukee. There are no popular flight routes from Ontario to Milwaukee.

Search flight deals

How far is Ontario to Milwaukee-Mitchell by plane?
The straight-line distance from Ontario to Milwaukee-Mitchell is 1710.4 mi. Flights usually cover this in 6h 22m, depending on flying conditions and air traffic around both airports.
When did momondo last update prices for flights from Ontario Airport to Milwaukee-Mitchell Airport?
Prices for flights from Ontario Airport to Milwaukee-Mitchell Airport are updated daily.
How many operators does momondo search for flights from Ontario Airport to Milwaukee-Mitchell Airport?
As of January 2026, there are 4 operators available to choose from for flights from Ontario Airport to Milwaukee-Mitchell Airport.
How old do you have to be to fly from Ontario Airport to Milwaukee-Mitchell Airport?
Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Ontario Airport to Milwaukee-Mitchell Airport.
What documentation or ID do you need to fly to Milwaukee-Mitchell Airport?
The travel and health documents required for your trip to Milwaukee-Mitchell Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Milwaukee-Mitchell Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.
What is the most popular airline from Ontario to Milwaukee?
momondo data reveals that the most frequently booked airline on the route from Ontario to Milwaukee is Southwest, representing 55% of all bookings. The subsequent popular airlines are American Airlines at 26%, United Airlines at 13%, and Delta at 6%.

Best airlines flying from Ontario to Milwaukee

Compare and see reviews for airlines that fly from Ontario to Milwaukee with momondo

Airline	Rating	Free Cancellation	Price
Delta	PriceFrom $253	Free Cancellation	Rating 7.9 8,124 reviews	Search Delta flights
American Airlines	PriceFrom $276	Free Cancellation	Rating 7.2 11,201 reviews	Search American Airlines flights
United Airlines	PriceFrom $309	Free Cancellation	Rating 7.4 9,212 reviews	Search United Airlines flights
Southwest	PriceFrom $330	Free Cancellation	Rating 8.0 4,267 reviews	Search Southwest flights

Sheboygan

Waukesha

Wauwatosa

Oak Creek

Mequon

Glendale

Pewaukee

Kohler

West Bend

Port Washington

New Berlin

Grafton

Why use momondo?

Why should I use momondo to find a flight deal from Ontario to Milwaukee?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Ontario to Milwaukee. momondo saves you time and could save you money on your trip.

Can I find flights from Ontario to Milwaukee with flexible booking policies on momondo?

Yes. momondo allows you to filter the results for Ontario to Milwaukee flights to just show those with flexible booking policies.

How can momondo help me find flights from Ontario to Milwaukee?

momondo provides multiple filters to help you find the best flight to Milwaukee from Ontario. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

I’m not ready to book a flight from Ontario to Milwaukee right now. Can momondo alert me if prices change?

Price alerts on flights to Milwaukee from Ontario are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.