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$161+ 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 4/8. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SDF
Apr 18 — Apr 251
Sat 4/18
Sat 4/25
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 March 19, 2026.

This United Airlines deal was found by Cheapflights users on 3/17. 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.
Tue 4/141:34 pm
ONT
-
SDF
1 stop6h 05m
United Airlines
Tue 4/213:30 pm
SDF
-
ONT
1 stop9h 20m
United Airlines
Deal found 3/17$321
This Delta deal was found by Cheapflights users on 3/18. 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 4/2110:15 pm
ONT
-
SDF
1 stop7h 37m
Delta
Sat 4/257:05 am
SDF
-
ONT
1 stop7h 31m
Delta
Deal found 3/18$327
This Southwest deal was found by Cheapflights users on 3/17. 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.
Tue 4/149:45 pm
ONT
-
SDF
2 stops9h 05m
Southwest
Tue 4/213:30 pm
SDF
-
ONT
2 stops9h 00m
Southwest
Deal found 3/17$331
This Delta deal was found by Cheapflights users on 3/19. 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 4/1512:49 pm
ONT
-
SDF
1 stop8h 10m
Delta
Sat 4/186:04 am
SDF
-
ONT
2 stops9h 10m
Delta
Deal found 3/19$332
This Delta deal was found by Cheapflights users on 3/16. 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 4/1410:15 pm
ONT
-
SDF
1 stop9h 11m
Delta
Thu 4/307:40 pm
SDF
-
ONT
1 stop7h 04m
Delta
Deal found 3/16$333
This American Airlines deal was found by Cheapflights users on 3/18. 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.
Sat 5/910:26 pm
ONT
-
SDF
1 stop7h 12m
American Airlines
Sat 5/167:55 pm
SDF
-
ONT
1 stop6h 51m
American Airlines
Deal found 3/18$335
This Southwest deal was found by Cheapflights users on 3/18. 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 4/169:55 pm
ONT
-
SDF
2 stops9h 00m
Southwest
Thu 4/2312:20 pm
SDF
-
ONT
1 stop7h 05m
Southwest
Deal found 3/18$338
This American Airlines deal was found by Cheapflights users on 3/16. 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.
Sat 4/256:15 am
ONT
-
SDF
2 stops10h 09m
American Airlines
Tue 4/289:00 am
SDF
-
ONT
2 stops10h 22m
American Airlines
Deal found 3/16$343
This American Airlines deal was found by Cheapflights users on 3/18. 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 5/142:08 pm
ONT
-
SDF
1 stop6h 03m
American Airlines
Sat 5/165:41 pm
SDF
-
ONT
1 stop9h 05m
American Airlines
Deal found 3/18$349

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 March 19, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$321
(United Airlines)

One-way from

$161
(American Airlines)

Popular in

January

Cheapest in

July

Average price

$466
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. 22% potential increase in price ($142 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 9% potential price decrease ($44 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 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 March 19, 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
Quickest round-trip

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Thu 5/7

11:55 pm-9:55 am

1 stop7h 00m

Louisville Intl

Sat 5/9

5:45 pm-8:45 pm

1 stop6h 00m

$333

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Thu 5/7

12:40 pm-12:15 am

1 stop8h 35m

Louisville Intl

Fri 5/8

6:30 am-11:20 am

1 stop7h 50m

$395

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Sat 4/18

6:00 am-6:10 pm

2 stops9h 10m

Louisville Intl

Sun 4/19

8:20 pm-12:10 am

1 stop6h 50m

$400

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Mon 6/1

12:40 pm-12:15 am

1 stop8h 35m

Louisville Intl

Fri 6/5

1:10 pm-8:10 pm

2 stops10h 00m

$400

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Sat 4/25

6:05 am-8:16 pm

2 stops11h 11m

Louisville Intl

Wed 4/29

1:55 pm-9:50 pm

2 stops10h 55m

$437

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Sat 4/4

5:10 am-2:31 pm

1 stop6h 21m

Louisville Intl

Tue 4/7

3:36 pm-8:36 pm

1 stop8h 00m

$443

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Tue 4/21

5:10 am-2:31 pm

1 stop6h 21m

Louisville Intl

Sat 4/25

3:36 pm-10:45 pm

2 stops10h 09m

$448

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Mon 6/1

9:50 am-11:52 pm

2 stops11h 02m

Louisville Intl

Sun 6/7

7:00 am-11:20 am

1 stop7h 20m

$473

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Fri 4/17

12:49 pm-10:50 pm

1 stop7h 01m

Louisville Intl

Fri 4/24

7:05 am-11:36 am

1 stop7h 31m

$487

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Fri 6/19

11:55 pm-10:00 am

1 stop7h 05m

Louisville Intl

Fri 6/26

8:45 am-2:00 pm

1 stop8h 15m

$498

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/15

Showing 1-10 of 23 resultsSorted by cheapest first
1
2
3

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 March.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust 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, June is the cheapest month in which you can book a flight from Ontario to Louisville (average of $67). Flying from Ontario to Louisville in February is currently the most expensive (average of $220). 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 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 March 19, 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
4,319 reviews

Comfort

8.0

Overall

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

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
4,319 reviews
Southwest
8.0
Very good
4,319 reviews

Comfort

8.0

Overall

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

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
8,292 reviews
Southwest
8.0
Very good
4,319 reviews

Comfort

8.0

Overall

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

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
9,439 reviews
Southwest
8.0
Very good
4,319 reviews

Comfort

8.0

Overall

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

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
11,472 reviews
Southwest
8.0
Very good
4,319 reviews

Comfort

8.0

Overall

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

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, Southwest, and United Airlines fly from Ontario to Louisville in about 6h 41m. The time it takes to get you to your destination can typically vary by up to 4h 54m. 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 United Airlines and American Airlines, with the lowest prices starting at $320 and $338, respectively. Delta is currently priced 51% 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 American Airlines, which is currently one of the cheapest options available, starting at $158. Southwest flights start at $160 while deals on United Airlines start at $195 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, June is the cheapest month in which you can book a flight from Ontario to Louisville (average of $67). Flying from Ontario to Louisville in February is currently the most expensive (average of $220). 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
Shepherdsville
Jeffersonville
Elizabethtown
Corydon
Bardstown

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Alternative routes for Ontario to Louisville

See prices for flight routes from nearby airports that may be better suited for you.
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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 March 19, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$238Average$522FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$320Average$443FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$338Average$477FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$342Average$446FlexibilityNo cancel feeOn-time63%

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