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$129+ Cheap flights from Louisville to Ontario (SDF - 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 10/6. Fares are subject to change and may not be available on all flights or dates of travel.
SDF — ONT
Oct 11 — Oct 181
Sat 10/11
Sat 10/18
1 adult, Economy
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Cheap flight deals from Louisville to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from Louisville (SDF) 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 11, 2025.

Round-trip from

$251
(Kiwi.com)

One-way from

$129
(Kiwi.com)

Popular in

January

Cheapest in

April

Average price

$501
From Louisville Intl to Ontario
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One-way flight from Louisville Intl to Ontario
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Highest demand for flights based on searches. 20% potential increase in price ($129 potential increase over avg. RT price).
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Cheapest flight prices on average. 5% potential price decrease ($27 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 Louisville to Ontario

Cheapest flights from Louisville to Ontario
Explore the most affordable flight options available from Louisville to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 11, 2025.

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.
Mon 10/62:57 pmSDF - ONT
1 stop8h 59mMultiple Airlines
Wed 10/88:00 amONT - SDF
1 stop27h 02mMultiple Airlines
Deal found 9/9$251
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/145:20 pmSDF - ONT
1 stop22h 17mMultiple Airlines
Thu 11/206:30 amONT - SDF
1 stop6h 42mMultiple Airlines
Deal found 9/11$254
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 9/307:10 amSDF - ONT
1 stop6h 32mDelta
Tue 9/3010:00 pmONT - SDF
1 stop7h 49mDelta
Deal found 9/10$277
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/65:30 pmSDF - ONT
1 stop8h 20mSouthwest
Wed 10/83:50 pmONT - SDF
1 stop5h 40mSouthwest
Deal found 9/10$280
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 9/306:00 amSDF - ONT
1 stop7h 42mDelta
Fri 10/310:00 pmONT - SDF
1 stop8h 27mDelta
Deal found 9/10$286
This American 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/169:44 amSDF - ONT
1 stop7h 17mAmerican Airlines
Fri 10/3110:57 amONT - SDF
1 stop8h 28mAmerican Airlines
Deal found 9/10$295
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 10/2112:54 pmSDF - ONT
1 stop9h 25mDelta
Sun 10/2610:00 pmONT - SDF
1 stop7h 54mDelta
Deal found 9/10$301
This American Airlines 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/87:32 amSDF - ONT
1 stop9h 11mAmerican Airlines
Wed 10/2210:09 amONT - SDF
2 stops10h 15mAmerican Airlines
Deal found 9/11$305
This American 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/64:44 pmSDF - ONT
1 stop8h 34mAmerican Airlines
Wed 10/810:57 amONT - SDF
1 stop8h 28mAmerican Airlines
Deal found 9/10$317
This American Airlines 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/304:43 pmSDF - ONT
1 stop8h 50mAmerican Airlines
Wed 10/18:15 amONT - SDF
1 stop6h 19mAmerican Airlines
Deal found 9/11$320

Cheapflights Fare Finder

 
Customize your flight search to find flights from Louisville 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 11, 2025.
Use the filters below to find and compare flights from Louisville to Ontario that are best for you.

Fly from

Louisville

Fly to

Ontario

Route

Depart

Return

Price

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Fri 11/14

5:20 pm-12:37 pm

1 stop22h 17m

Ontario

Thu 11/20

6:30 am-4:12 pm

1 stop6h 42m

$254

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Tue 9/30

7:10 am-10:42 am

1 stop6h 32m

Ontario

Tue 9/30

10:00 pm-8:49 am

1 stop7h 49m

$277

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Mon 10/6

5:30 pm-10:50 pm

1 stop8h 20m

Ontario

Wed 10/8

3:50 pm-12:30 am

1 stop5h 40m

$280

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Thu 10/2

5:53 pm-10:23 pm

1 stop7h 30m

Ontario

Fri 10/3

10:00 pm-9:27 am

1 stop8h 27m

$286

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Tue 10/21

12:54 pm-7:19 pm

1 stop9h 25m

Ontario

Sun 10/26

10:00 pm-8:54 am

1 stop7h 54m

$301

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Wed 10/8

7:32 am-1:43 pm

1 stop9h 11m

Ontario

Wed 10/22

10:09 am-11:24 pm

2 stops10h 15m

$305

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Sun 2/8

5:35 am-12:47 pm

2 stops10h 12m

Ontario

Sun 2/15

1:00 pm-9:57 pm

1 stop5h 57m

$330

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Wed 10/8

5:48 pm-10:30 pm

1 stop7h 42m

Ontario

Wed 10/22

1:15 pm-10:30 pm

1 stop6h 15m

$333

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Sat 10/25

3:30 pm-8:24 pm

1 stop7h 54m

Ontario

Sat 11/1

7:00 am-5:16 pm

1 stop7h 16m

$333

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Wed 10/1

3:30 pm-8:24 pm

1 stop7h 54m

Ontario

Wed 10/8

1:15 pm-10:30 pm

1 stop6h 15m

$333

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/9

Showing 1-10 of 22 results
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Best time to book a flight from Louisville to Ontario

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

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

Currently, August is the cheapest month in which you can book a flight from Louisville to Ontario (average of $246). Flying from Louisville 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 SDF to ONT?

Find hourly flight availability from Louisville 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 11, 2025.

When flying from Louisville to Ontario, the time of day you fly usually plays a role in the price. Save by searching for a flight in the evening, which can drop the price by up to 38% versus a flight at noon.

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 11, 2025.
Get a feel of what it's like to fly with Southwest, Delta, and United Airlines from Louisville to Ontario by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,248 reviews

Comfort

8.0

Entertainment

7.5

Overall

8.0

Food

7.0

Crew

8.6

Boarding

8.1

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

Comfort

8.0

Entertainment

7.5

Overall

8.0

Food

7.0

Crew

8.6

Boarding

8.1

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

Comfort

8.0

Entertainment

7.5

Overall

8.0

Food

7.0

Crew

8.6

Boarding

8.1

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

Comfort

8.0

Entertainment

7.5

Overall

8.0

Food

7.0

Crew

8.6

Boarding

8.1

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

Comfort

8.0

Entertainment

7.5

Overall

8.0

Food

7.0

Crew

8.6

Boarding

8.1

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 Louisville 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 Louisville to Ontario?

    Southwest, Delta, and American Airlines can get you from Louisville to Ontario in just under 7h 30m. Your travel time can differ by up to 1h 41m. Airlines will cover a distance of 1791 mi. Both multi-stop and nonstop flights can be found to your destination and back.

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

    United Airlines, at $257, was found to be the cheapest airline from Louisville to Ontario.Alternate airlines to your destination round-trip include American Airlines and Delta. United Airlines is currently priced 47% below the average price you’ll pay for this route.

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

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

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

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

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

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

    Currently, August is the cheapest month in which you can book a flight from Louisville to Ontario (average of $246). Flying from Louisville 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 Louisville to Ontario

Discover the top 4 airlines that operate flights from Louisville 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 11, 2025.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$257Average$606FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$268Average$486FlexibilityNo cancel feeOn-time71%
DeltaCheapest$288Average$403FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$315Average$446FlexibilityNo cancel feeOn-time63%

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