HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Louisville

$138+ 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 1/24. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SDF
Dec 6 — Dec 131
Sat 12/6
Sat 12/13
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Ontario to Louisville 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.

Find 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 November 6, 2025.

This American Airlines deal was found by Cheapflights users on 11/5. 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 12/187:10 amONT - SDF
1 stop7h 21mAmerican Airlines
Mon 12/228:12 pmSDF - ONT
1 stop6h 34mAmerican Airlines
Deal found 11/5$335
This Kiwi.com deal was found by Cheapflights users on 11/5. 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 12/56:19 pmONT - SDF
2 stops40h 56mMultiple Airlines
Fri 12/129:43 amSDF - ONT
1 stop17h 05mMultiple Airlines
Deal found 11/5$340
This Delta deal was found by Cheapflights users on 11/5. 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 12/412:12 pmONT - SDF
1 stop8h 47mDelta
Sun 12/76:00 amSDF - ONT
1 stop8h 02mDelta
Deal found 11/5$386
This American Airlines deal was found by Cheapflights users on 11/5. 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 12/46:17 amONT - SDF
2 stops9h 56mAmerican Airlines
Sun 12/73:39 pmSDF - ONT
2 stops9h 21mAmerican Airlines
Deal found 11/5$396
This American Airlines deal was found by Cheapflights users on 11/5. 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 12/256:10 amONT - SDF
1 stop8h 18mAmerican Airlines
Wed 12/316:35 amSDF - ONT
1 stop8h 18mAmerican Airlines
Deal found 11/5$410
This United Airlines deal was found by Cheapflights users on 11/5. 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.
Thu 12/255:05 amONT - SDF
1 stop6h 17mUnited Airlines
Thu 1/16:11 pmSDF - ONT
1 stop7h 14mUnited Airlines
Deal found 11/5$411
This Delta deal was found by Cheapflights users on 11/5. 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 12/512:12 pmONT - SDF
1 stop8h 47mDelta
Sun 12/76:16 pmSDF - ONT
1 stop7h 48mDelta
Deal found 11/5$437
This Delta deal was found by Cheapflights users on 11/5. 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 11/2010:25 pmONT - SDF
1 stop8h 27mDelta
Mon 11/247:05 amSDF - ONT
1 stop7h 01mDelta
Deal found 11/5$439

Cheap 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 November 6, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$335
(American Airlines)

One-way from

$138
(Kiwi.com)

Popular in

March

Cheapest in

February

Average price

$527
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
High demand for flights, 7% potential price rise
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($7 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in November 2025
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 November 6, 2025.
Use the filters below to find and compare flights from Ontario to Louisville that are best for you.

Fly from

Ontario

Fly to

Louisville

Route

Depart

Return

Price

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Tue 4/14

12:00 pm-10:32 pm

1 stop7h 32m

Louisville Intl

Wed 4/15

5:45 pm-10:09 pm

1 stop7h 24m

$321

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Wed 2/4

7:16 am-5:33 pm

1 stop7h 17m

Louisville Intl

Sun 2/8

6:32 pm-10:48 pm

1 stop7h 16m

$379

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Wed 2/4

1:24 pm-10:44 pm

1 stop6h 20m

Louisville Intl

Sun 2/8

11:10 am-8:58 pm

2 stops12h 48m

$384

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Mon 12/8

10:25 pm-9:50 am

1 stop8h 25m

Louisville Intl

Fri 12/12

6:00 am-11:02 am

1 stop8h 02m

$386

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Thu 1/22

10:40 am-10:10 pm

2 stops8h 30m

Louisville Intl

Sun 1/25

1:30 pm-5:35 pm

1 stop7h 05m

$391

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Thu 12/25

6:10 am-5:28 pm

1 stop8h 18m

Louisville Intl

Wed 12/31

6:35 am-11:53 am

1 stop8h 18m

$410

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Thu 12/25

5:05 am-2:22 pm

1 stop6h 17m

Louisville Intl

Thu 1/1

6:11 pm-10:25 pm

1 stop7h 14m

$411

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Fri 12/5

12:12 pm-11:59 pm

1 stop8h 47m

Louisville Intl

Sun 12/7

6:16 pm-11:04 pm

1 stop7h 48m

$437

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Wed 12/10

6:00 am-5:38 pm

1 stop8h 38m

$161

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Tue 12/9

5:05 am-2:30 pm

1 stop6h 25m

$161

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/6

Showing 1-10 of 18 results
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 November.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
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 eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Ontario-Louisville flight deals on Cheapflights vs. eDreams >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 eDreams the most. eDreams 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 $71). Flying from Ontario to Louisville in November is currently the most expensive (average of $182). 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 ONT to SDF?

Find hourly flight availability from Ontario to Louisville. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated November 6, 2025.

Unlike in the afternoon, when flights are generally more expensive, you can save up to 8% on flights from Ontario to Louisville by exploring options for tickets in the evening.

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 November 6, 2025.
Read reviews from past customers who have flown Southwest, Delta, and United 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
4,241 reviews

Food

7.0

Comfort

8.0

Crew

8.6

Entertainment

7.5

Overall

8.0

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
4,241 reviews
Southwest
8.0
Very good
4,241 reviews

Food

7.0

Comfort

8.0

Crew

8.6

Entertainment

7.5

Overall

8.0

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
7.9
Good
8,001 reviews
Southwest
8.0
Very good
4,241 reviews

Food

7.0

Comfort

8.0

Crew

8.6

Entertainment

7.5

Overall

8.0

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
9,007 reviews
Southwest
8.0
Very good
4,241 reviews

Food

7.0

Comfort

8.0

Crew

8.6

Entertainment

7.5

Overall

8.0

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
11,040 reviews
Southwest
8.0
Very good
4,241 reviews

Food

7.0

Comfort

8.0

Crew

8.6

Entertainment

7.5

Overall

8.0

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 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, American Airlines, and United Airlines fly from Ontario to Louisville in about 6h 20m. The time it takes to get you to your destination can typically vary by up to 1h 12m. 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 American Airlines is currently your cheapest option to Louisville, with prices starting at $342. Additional round-trip tickets that might be worth considering are offered by Southwest and United Airlines, with the lowest prices starting at $342 and $343, respectively. American Airlines is currently priced 28% 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 $161. United Airlines flights start at $161 while deals on Delta start at $161 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 $71). Flying from Ontario to Louisville in November is currently the most expensive (average of $182). 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

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 Ontario to Louisville

See prices for flight routes from nearby airports that may be better suited for you.
Los Angeles to Nashville flights
San Francisco to Nashville flights
Ontario to Nashville flights
Santa Ana to Nashville flights
San Diego to Nashville flights
Burbank to Nashville flights
Los Angeles to Cincinnati flights
San Francisco to Cincinnati flights
Las Vegas to Nashville flights
Los Angeles to Knoxville flights
Sacramento to Nashville flights
Los Angeles to Louisville flights
San Jose to Nashville flights
Ontario to Cincinnati flights
Long Beach to Nashville flights
Ontario to Knoxville flights
San Francisco to Knoxville flights
Sacramento to Cincinnati flights
Fresno to Nashville flights
Oakland to Nashville flights
Reno to Nashville flights
San Diego to Cincinnati flights
San Francisco to Lexington flights
Los Angeles to Lexington flights
Palm Springs to Nashville flights
San Diego to Knoxville flights
Sacramento to Knoxville flights
Santa Ana to Cincinnati flights
Las Vegas to Cincinnati flights
San Diego to Louisville flights
Santa Barbara to Nashville flights
San Jose to Knoxville flights
San Francisco to Louisville flights
San Jose to Cincinnati flights
Las Vegas to Louisville flights
Oakland to Cincinnati flights
Burbank to Knoxville flights
San Jose to Louisville flights
Sacramento to Louisville flights
Santa Ana to Louisville flights
Santa Ana to Lexington flights
San Diego to Lexington flights
San Jose to Lexington flights
Burbank to Cincinnati flights
Ontario to Lexington flights
Fresno to Louisville flights
Santa Ana to Knoxville flights
San Luis Obispo to Cincinnati flights
San Luis Obispo to Nashville flights

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 November 6, 2025.
AirlineCheapestAverageFlexibilityOn-time
SouthwestCheapest$342Average$462FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$342Average$516FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$343Average$506FlexibilityNo cancel feeOn-time69%
DeltaCheapest$346Average$507FlexibilityNo cancel feeOn-timeN/A

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.