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$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 1/21. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SDF
Jan 3 — Jan 101
Sat 1/3
Sat 1/10
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 December 4, 2025.

This United Airlines deal was found by Cheapflights users on 12/2. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/311:40 pmONT - SDF
1 stop5h 44mUnited Airlines
Wed 1/79:50 amSDF - ONT
2 stops14h 08mUnited Airlines
Deal found 12/2$334
This Southwest deal was found by Cheapflights users on 12/2. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/313:10 pmONT - SDF
1 stop5h 35mSouthwest
Wed 1/76:00 amSDF - ONT
1 stop7h 20mSouthwest
Deal found 12/2$353
This American Airlines deal was found by Cheapflights users on 12/2. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/319:53 amONT - SDF
2 stops9h 01mAmerican Airlines
Wed 1/78:07 amSDF - ONT
2 stops10h 58mAmerican Airlines
Deal found 12/2$354
This United Airlines deal was found by Cheapflights users on 12/3. 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
Tue 1/63:22 pmSDF - ONT
1 stop8h 36mUnited Airlines
Deal found 12/3$368
This American Airlines deal was found by Cheapflights users on 12/2. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/2612:45 pmONT - SDF
1 stop5h 55mAmerican Airlines
Thu 1/18:12 pmSDF - ONT
1 stop6h 34mAmerican Airlines
Deal found 12/2$409
This Delta deal was found by Cheapflights users on 12/3. 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.
Sun 12/2110:29 pmONT - SDF
1 stop8h 00mDelta
Thu 1/83:37 pmSDF - ONT
1 stop8h 28mDelta
Deal found 12/3$438
This United Airlines deal was found by Cheapflights users on 12/4. 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 12/235:05 amONT - SDF
1 stop6h 17mUnited Airlines
Tue 1/69:00 amSDF - ONT
1 stop6h 47mUnited Airlines
Deal found 12/4$488
This United Airlines deal was found by Cheapflights users on 12/3. 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.
Sun 12/215:05 amONT - SDF
1 stop6h 17mUnited Airlines
Thu 1/811:10 amSDF - ONT
2 stops12h 48mUnited Airlines
Deal found 12/3$493
This United Airlines deal was found by Cheapflights users on 12/3. 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.
Fri 12/265:05 amONT - SDF
1 stop6h 17mUnited Airlines
Thu 1/16:11 pmSDF - ONT
1 stop7h 14mUnited Airlines
Deal found 12/3$497

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 December 4, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$212
(American Airlines)

One-way from

$138
(American Airlines)

Popular in

March

Cheapest in

February

Average price

$522
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 December 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 December 4, 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

Mon 1/12

10:30 pm-9:28 am

1 stop7h 58m

Louisville Intl

Wed 1/14

7:05 am-11:31 am

1 stop7h 26m

$277

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Wed 12/31

1:40 pm-10:24 pm

1 stop5h 44m

Louisville Intl

Wed 1/7

9:50 am-8:58 pm

2 stops14h 08m

$334

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Wed 12/31

3:10 pm-11:45 pm

1 stop5h 35m

Louisville Intl

Wed 1/7

6:00 am-10:20 am

1 stop7h 20m

$353

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Sun 1/18

12:41 pm-11:55 pm

1 stop8h 14m

Louisville Intl

Sat 1/24

5:35 am-11:31 am

1 stop8h 56m

$357

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Sun 1/11

10:30 pm-9:28 am

1 stop7h 58m

Louisville Intl

Tue 1/13

3:37 pm-9:05 pm

1 stop8h 28m

$357

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Thu 2/19

1:45 pm-10:37 pm

1 stop5h 52m

Louisville Intl

Mon 2/23

5:54 pm-10:00 pm

2 stops31h 06m

$393

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Thu 2/26

1:45 pm-10:37 pm

1 stop5h 52m

Louisville Intl

Mon 3/2

9:00 am-8:50 pm

2 stops14h 50m

$393

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Sun 1/11

10:30 pm-9:28 am

1 stop7h 58m

Louisville Intl

Mon 1/12

3:37 pm-9:05 pm

1 stop8h 28m

$408

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Thu 2/12

1:45 pm-10:37 pm

1 stop5h 52m

Louisville Intl

Sun 2/15

5:35 am-8:50 pm

2 stops18h 15m

$420

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Mon 1/5

1:40 pm-10:24 pm

1 stop5h 44m

Louisville Intl

Wed 1/7

3:22 pm-8:58 pm

1 stop8h 36m

$428

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/3

Showing 1-10 of 20 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 December.
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 $183). 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 December 4, 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.

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 December 4, 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
4,250 reviews

Boarding

8.1

Entertainment

7.5

Food

7.0

Comfort

8.0

Crew

8.6

Overall

8.0

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
4,250 reviews
Southwest
8.0
Very good
4,250 reviews

Boarding

8.1

Entertainment

7.5

Food

7.0

Comfort

8.0

Crew

8.6

Overall

8.0

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
8,011 reviews
Southwest
8.0
Very good
4,250 reviews

Boarding

8.1

Entertainment

7.5

Food

7.0

Comfort

8.0

Crew

8.6

Overall

8.0

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
9,066 reviews
Southwest
8.0
Very good
4,250 reviews

Boarding

8.1

Entertainment

7.5

Food

7.0

Comfort

8.0

Crew

8.6

Overall

8.0

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
7.2
Good
11,047 reviews
Southwest
8.0
Very good
4,250 reviews

Boarding

8.1

Entertainment

7.5

Food

7.0

Comfort

8.0

Crew

8.6

Overall

8.0

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 American Airlines and United Airlines fly from Ontario to Louisville in about 8h 33m. The time it takes to get you to your destination can typically vary by up to 2h 53m. 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 27% 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 $189 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 $183). 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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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 December 4, 2025.
AirlineCheapestAverageFlexibilityOn-time
SouthwestCheapest$342Average$456FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$342Average$516FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$343Average$505FlexibilityNo cancel feeOn-time69%
DeltaCheapest$346Average$466FlexibilityNo cancel feeOn-timeN/A

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