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$139+ Cheap flights from Ontario to Louisville (ONT - SDF)

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 9/2. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SDF
Jul 2 — Jul 91
Thu 7/2
Thu 7/9
1 adult, Economy
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Cheap flight deals from Ontario to Louisville

Cheapest flights from Ontario to Louisville
Explore the most affordable flight options available from Ontario to Louisville. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 2, 2026.

This Delta deal was found by Cheapflights users on 5/30. 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 8/2012:00 pm
ONT
-
SDF
1 stop7h 10m
Delta
Sat 8/226:00 am
SDF
-
ONT
1 stop7h 42m
Delta
Deal found 5/30$297
This American Airlines deal was found by Cheapflights users on 5/30. 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 9/107:11 pm
ONT
-
SDF
2 stops11h 32m
American Airlines
Mon 9/144:19 pm
SDF
-
ONT
1 stop9h 18m
American Airlines
Deal found 5/30$328
This American Airlines deal was found by Cheapflights users on 5/31. 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 9/912:37 pm
ONT
-
SDF
1 stop6h 06m
American Airlines
Mon 9/144:19 pm
SDF
-
ONT
1 stop9h 18m
American Airlines
Deal found 5/31$338
This Southwest deal was found by Cheapflights users on 5/28. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/1511:55 pm
ONT
-
SDF
1 stop7h 20m
Southwest
Tue 10/202:20 pm
SDF
-
ONT
1 stop6h 25m
Southwest
Deal found 5/28$350
This Delta deal was found by Cheapflights users on 5/29. 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 8/412:00 pm
ONT
-
SDF
1 stop9h 34m
Delta
Tue 8/117:05 am
SDF
-
ONT
1 stop6h 37m
Delta
Deal found 5/29$351
This Delta deal was found by Cheapflights users on 6/2. 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 8/2112:00 pm
ONT
-
SDF
1 stop9h 34m
Delta
Sat 8/227:05 am
SDF
-
ONT
1 stop6h 37m
Delta
Deal found 6/2$356
This Delta deal was found by Cheapflights users on 6/2. 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 8/610:00 pm
ONT
-
SDF
1 stop7h 46m
Delta
Wed 8/127:05 am
SDF
-
ONT
1 stop6h 37m
Delta
Deal found 6/2$366

Find flight deals from Ontario to Louisville

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to Louisville (SDF). 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 June 2, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$297
(Delta)

One-way from

$139
(American Airlines)

Popular in

January

Cheapest in

July

Average price

$456
Provider with most accurate pricing for Ontario-Louisville Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for Ontario-Louisville Intl flights.
Search Deals
From Ontario to Louisville Intl
Search Deals
One-way flight from Ontario to Louisville Intl
Search Deals
Highest demand for flights based on searches. 18% potential increase in price ($116 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 8% potential price decrease ($42 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in June 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Ontario to Louisville 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 June 2, 2026.
Use the filters below to find and compare flights from Ontario to Louisville that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Tue 8/11

9:15 am-7:59 pm

1 stop7h 44m

Louisville Intl

Wed 8/12

8:00 am-12:50 pm

1 stop7h 50m

$377

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Sat 9/19

5:00 am-2:29 pm

1 stop6h 29m

Louisville Intl

Tue 9/22

3:25 pm-8:53 pm

1 stop8h 28m

$387

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Wed 7/15

5:15 am-3:35 pm

1 stop7h 20m

Louisville Intl

Wed 7/22

5:35 am-12:05 pm

1 stop9h 30m

$401

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Tue 8/4

11:55 pm-11:15 am

1 stop8h 20m

Louisville Intl

Fri 8/7

11:05 am-3:05 pm

1 stop7h 00m

$404

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Thu 7/23

9:40 pm-10:05 am

2 stops9h 25m

Louisville Intl

Thu 7/30

12:35 pm-3:05 pm

1 stop5h 30m

$458

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Mon 6/15

12:40 pm-12:25 am

1 stop8h 45m

Louisville Intl

Sun 6/28

6:30 am-11:40 am

1 stop8h 10m

$547

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Sun 6/28

11:50 am-9:19 pm

1 stop6h 29m

Louisville Intl

Fri 7/3

4:40 pm-9:48 pm

1 stop8h 08m

$598
Quickest round-trip

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Sun 6/21

10:00 pm-8:57 am

1 stop7h 57m

Louisville Intl

Sun 6/28

7:05 am-10:40 am

1 stop6h 35m

$608
Cheapest one-way

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Tue 7/28

11:55 pm-10:05 am

1 stop7h 10m

$176

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Tue 8/4

12:00 pm-12:34 am

1 stop9h 34m

$176

Flights are sorted by cheapest round-trip flights first.

Deals found on 5/30

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

Compare providers for flights from Ontario to Louisville

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 Ontario to Louisville in June.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
CheapTicketsDealPrice Accuracy1 starTrust Score*3 stars
PricelinePrice Accuracy1 starTrust 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 Ontario-Louisville flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-Louisville flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-Louisville flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Ontario-Louisville 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 Ontario-Louisville 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 Ontario to Louisville

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

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

Currently, July is the cheapest month in which you can book a flight from Ontario to Louisville (average of $379). Flying from Ontario to Louisville in January is currently the most expensive (average of $976). 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.

How much does it cost to fly round-trip from Ontario to Louisville?

Reviews of airlines servicing Louisville

Get insights into the airlines that provide service to Louisville. 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 Louisville. Reviews last updated June 2, 2026.
Read reviews from past customers who have flown Southwest,Delta, andUnited Airlines from Ontario to Louisville. 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
4,258 reviews

Entertainment

7.5

Overall

8.0

Comfort

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
Southwest
8.0
Very good
4,258 reviews
Southwest
8.0
Very good
4,258 reviews

Entertainment

7.5

Overall

8.0

Comfort

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
Delta
7.9
Good
8,398 reviews
Southwest
8.0
Very good
4,258 reviews

Entertainment

7.5

Overall

8.0

Comfort

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
United Airlines
7.4
Good
9,778 reviews
Southwest
8.0
Very good
4,258 reviews

Entertainment

7.5

Overall

8.0

Comfort

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
American Airlines
7.1
Good
11,640 reviews
Southwest
8.0
Very good
4,258 reviews

Entertainment

7.5

Overall

8.0

Comfort

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.

Related info for your journey

Find useful and relevant information for your journey from Ontario to Louisville. 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 Louisville?

    Airlines like Delta, United Airlines, and Southwest fly from Ontario to Louisville in about 6h 29m. The time it takes to get you to your destination can typically vary by up to 3h 05m. There are 1791 mi between Ontario and Louisville. This flight may include one or multiple stops.

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

    Flying on Delta is currently your cheapest option to Louisville, with prices starting at $238. Additional round-trip tickets that might be worth considering are offered by Southwest and United Airlines, with the lowest prices starting at $341 and $343, respectively. Delta is currently priced 54% below the average price you’ll pay for this route.

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

    To fly one-way, consider booking your trip with Delta, which is currently one of the cheapest options available, starting at $143. American Airlines flights start at $158 while deals on Southwest start at $160 one-way.

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

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

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

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

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

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

    Currently, July is the cheapest month in which you can book a flight from Ontario to Louisville (average of $379). Flying from Ontario to Louisville in January is currently the most expensive (average of $976). 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 Louisville?

Book flights to Louisville if you plan to visit one of these locations
Elizabethtown
Shepherdsville
Corydon
Jeffersonville
Bardstown

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Top 4 airlines flying from Ontario to Louisville

Discover the top 4 airlines that operate flights from Ontario to Louisville. 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 June 2, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$238Average$522FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$341Average$466FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$343Average$489FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$387Average$471FlexibilityNo cancel feeOn-time71%

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