HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Louisville

$154+ 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 6/4. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SDF
May 6 — May 131
Tue 5/6
Tue 5/13
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.

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 May 1, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$307
(Delta)

One-way from

$154
(Delta)

Popular in

March

Cheapest in

February

Average price

$511
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 ($8 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in May 2025
Search Deals

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 May 1, 2025.

This Delta deal was found by Cheapflights users on 4/30. 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.
Sat 5/3112:18 pmONT - SDF
1 stop8h 47mDelta
Tue 6/35:55 pmSDF - ONT
1 stop7h 34mDelta
Deal found 4/30$325
This American Airlines deal was found by Cheapflights users on 4/30. 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 8/710:50 amONT - SDF
1 stop6h 11mAmerican Airlines
Mon 8/116:21 pmSDF - ONT
1 stop6h 53mAmerican Airlines
Deal found 4/30$343
This United Airlines deal was found by Cheapflights users on 4/30. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/171:33 pmONT - SDF
1 stop5h 54mUnited Airlines
Mon 6/233:29 pmSDF - ONT
1 stop8h 35mUnited Airlines
Deal found 4/30$352
This Southwest deal was found by Cheapflights users on 5/1. 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 9/1812:45 pmONT - SDF
1 stop7h 45mSouthwest
Sun 9/216:20 amSDF - ONT
1 stop6h 15mSouthwest
Deal found 5/1$410
This Alaska Airlines deal was found by Cheapflights users on 4/30. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/66:00 amONT - SDF
2 stops13h 43mAlaska Airlines
Wed 8/1310:54 amSDF - ONT
2 stops16h 19mAlaska Airlines
Deal found 4/30$503

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 May 1, 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

Sat 8/30

12:00 pm-10:32 pm

1 stop7h 32m

Louisville Intl

Tue 9/2

5:45 pm-10:29 pm

1 stop7h 44m

$307

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Thu 8/7

10:50 am-8:01 pm

1 stop6h 11m

Louisville Intl

Mon 8/11

6:21 pm-10:14 pm

1 stop6h 53m

$343

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Tue 6/17

5:10 am-2:31 pm

1 stop6h 21m

Louisville Intl

Mon 6/23

3:29 pm-9:04 pm

1 stop8h 35m

$372

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Fri 8/29

5:20 am-5:40 pm

2 stops9h 20m

Louisville Intl

Mon 9/1

6:25 am-12:40 pm

2 stops9h 15m

$437

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Sun 6/1

6:00 am-9:03 pm

2 stops12h 03m

Louisville Intl

Tue 6/3

5:45 am-6:25 pm

2 stops15h 40m

$552

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Wed 6/4

12:18 pm-10:43 pm

1 stop7h 25m

$154

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Tue 7/1

5:05 am-2:23 pm

1 stop6h 18m

$194

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Fri 6/13

11:59 pm-12:15 pm

1 stop9h 16m

$198

OntarioLouisville

ONT - SDF

ONTSDF

Ontario

Wed 6/4

6:00 am-12:23 am

2 stops15h 23m

$224

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/29

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 May.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*2 stars
eDreamsPrice Accuracy3 starsTrust 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 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, January is the cheapest month in which you can book a flight from Ontario to Louisville (average of $299). Flying from Ontario to Louisville in April is currently the most expensive (average of $369). 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 May 1, 2025.

Unlike in the afternoon, when flights are generally more expensive, you can save up to 9% on flights from Ontario to Louisville by exploring options for tickets in the evening.

Rainfall in Louisville by month

Plan your trip to Louisville by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Louisville ranges from 3.1 - 5.3 inches per month. May is typically the wettest month, when rainfall can reach 5.3 in. September is typically the driest time to visit Louisville when rainfall is around 3.1 in.

Temperature in Louisville by month

Plan your trip to Louisville by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Louisville, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 78.8 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 35.6 F).

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 May 1, 2025.
Read reviews from past customers who have flown Alaska Airlines, Southwest and Delta from Ontario to Louisville. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
9,972 reviews

Food

7.1

Comfort

7.9

Crew

8.5

Entertainment

7.1

Overall

8.0

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Alaska Airlines
8.0
Very good
9,972 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Food

7.1

Comfort

7.9

Crew

8.5

Entertainment

7.1

Overall

8.0

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Southwest
8.0
Very good
4,294 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Food

7.1

Comfort

7.9

Crew

8.5

Entertainment

7.1

Overall

8.0

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Delta
8.0
Very good
7,934 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Food

7.1

Comfort

7.9

Crew

8.5

Entertainment

7.1

Overall

8.0

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
United Airlines
7.4
Good
8,696 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Food

7.1

Comfort

7.9

Crew

8.5

Entertainment

7.1

Overall

8.0

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Food

7.1

Comfort

7.9

Crew

8.5

Entertainment

7.1

Overall

8.0

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

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.

  • 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 $307. Additional round-trip tickets that might be worth considering are offered by American Airlines and United Airlines, with the lowest prices starting at $343 and $372, respectively. Delta is currently priced 36% 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 $154. United Airlines flights start at $199 while deals on Alaska Airlines start at $224 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, January is the cheapest month in which you can book a flight from Ontario to Louisville (average of $299). Flying from Ontario to Louisville in April is currently the most expensive (average of $369). 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 Ontario?

Book flights to Ontario if you plan to visit one of these locations
Jeffersonville
Corydon
Elizabethtown
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
Burbank to Nashville flights
San Diego to Nashville flights
Los Angeles to Cincinnati flights
Sacramento to Nashville flights
Las Vegas to Nashville flights
Oakland to Nashville flights
San Jose to Nashville flights
Long Beach to Nashville flights
Ontario to Cincinnati flights
Santa Ana to Cincinnati flights
Los Angeles to Lexington flights
San Francisco to Cincinnati flights
San Diego to Knoxville flights
Los Angeles to Knoxville flights
San Francisco to Knoxville flights
Fresno to Nashville flights
Las Vegas to Cincinnati flights
Ontario to Knoxville flights
Las Vegas to Knoxville flights
San Jose to Cincinnati flights
San Francisco to Louisville flights
Sacramento to Knoxville flights
Sacramento to Cincinnati flights
Ontario to Lexington flights
Oakland to Cincinnati flights
Los Angeles to Louisville flights
San Diego to Cincinnati flights
Palm Springs to Nashville flights
Santa Ana to Lexington flights
Reno to Cincinnati flights
Santa Ana to Knoxville flights
San Francisco to Lexington flights
Las Vegas to Lexington flights
San Jose to Knoxville flights
Burbank to Cincinnati flights
Reno to Nashville flights
Fresno to Lexington flights
Las Vegas to Louisville flights
Fresno to Louisville flights
Bakersfield to Nashville flights
Sacramento to Lexington flights
Reno to Knoxville flights
Santa Rosa to Nashville flights
Santa Barbara to Nashville flights
Fresno to Knoxville 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 May 1, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$326Average$499FlexibilityNo cancel feeOn-time71%
DeltaCheapest$346Average$416FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$354Average$505FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$367Average$478FlexibilityNo cancel feeOn-time63%

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.