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Ontario

$161+ Cheap flights from Louisville to Ontario (SDF - ONT)

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 1/9. Fares are subject to change and may not be available on all flights or dates of travel.
SDF — ONT
Jan 11 — Jan 181
Sun 1/11
Sun 1/18
1 adult, Economy
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Cheap flight deals from Louisville to Ontario

Cheapest flights from Louisville to Ontario
Explore the most affordable flight options available from Louisville to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 12, 2025.

This United Airlines deal was found by Cheapflights users on 12/9. 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 12/253:18 pmSDF - ONT
1 stop8h 49mUnited Airlines
Thu 1/11:40 pmONT - SDF
1 stop5h 44mUnited Airlines
Deal found 12/9$470
This United Airlines deal was found by Cheapflights users on 12/11. 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 12/243:18 pmSDF - ONT
1 stop8h 49mUnited Airlines
Thu 1/15:05 amONT - SDF
1 stop6h 17mUnited Airlines
Deal found 12/11$471
This Southwest deal was found by Cheapflights users on 12/11. 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 12/247:45 amSDF - ONT
1 stop7h 25mSouthwest
Fri 12/268:30 amONT - SDF
1 stop8h 05mSouthwest
Deal found 12/11$509
This United Airlines deal was found by Cheapflights users on 12/10. 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 12/313:18 pmSDF - ONT
1 stop8h 49mUnited Airlines
Thu 1/15:05 amONT - SDF
1 stop6h 17mUnited Airlines
Deal found 12/10$510
This United Airlines deal was found by Cheapflights users on 12/10. 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 12/313:18 pmSDF - ONT
1 stop8h 49mUnited Airlines
Fri 1/211:59 pmONT - SDF
1 stop7h 04mUnited Airlines
Deal found 12/10$518
This United Airlines deal was found by Cheapflights users on 12/10. 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 12/313:18 pmSDF - ONT
1 stop8h 49mUnited Airlines
Tue 1/65:05 amONT - SDF
1 stop6h 21mUnited Airlines
Deal found 12/10$520
This American Airlines deal was found by Cheapflights users on 12/11. 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 12/248:00 amSDF - ONT
2 stops11h 07mAmerican Airlines
Fri 12/266:20 amONT - SDF
2 stops8h 08mAmerican Airlines
Deal found 12/11$545
This United Airlines deal was found by Cheapflights users on 12/11. 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 12/243:18 pmSDF - ONT
1 stop8h 49mUnited Airlines
Fri 12/265:05 amONT - SDF
1 stop6h 17mUnited Airlines
Deal found 12/11$559

Find flight deals from Louisville to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from Louisville (SDF) to Ontario (ONT). 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 12, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$311
(Delta)

One-way from

$161
(Kiwi.com)

Popular in

January

Cheapest in

October

Average price

$434
Provider with most accurate pricing for Louisville Intl-Ontario flight deals.
Search Deals
Provider most trusted by Cheapflights users for Louisville Intl-Ontario flights.
Search Deals
From Louisville Intl to Ontario
Search Deals
One-way flight from Louisville Intl to Ontario
Search Deals
Highest demand for flights based on searches. 28% potential increase in price ($187 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 13% potential price decrease ($56 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 Louisville to Ontario 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 12, 2025.
Use the filters below to find and compare flights from Louisville to Ontario that are best for you.

Fly from

Louisville

Fly to

Ontario

Route

Depart

Return

Price

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Sun 1/18

3:37 pm-9:05 pm

1 stop8h 28m

Ontario

Sat 1/24

10:30 pm-9:26 am

1 stop7h 56m

$330

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Thu 2/5

3:32 pm-9:05 pm

1 stop8h 33m

Ontario

Sat 2/14

1:15 pm-11:58 pm

1 stop7h 43m

$330

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Sat 1/10

3:37 pm-9:05 pm

1 stop8h 28m

Ontario

Sat 1/17

10:30 pm-9:28 am

1 stop7h 58m

$350

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Sat 1/17

3:37 pm-9:05 pm

1 stop8h 28m

Ontario

Mon 1/19

10:30 pm-9:26 am

1 stop7h 56m

$379

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Fri 2/13

5:33 am-12:02 pm

1 stop9h 29m

Ontario

Sat 2/14

1:15 pm-11:58 pm

1 stop7h 43m

$390

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Sat 1/17

3:30 pm-9:58 pm

1 stop9h 28m

Ontario

Sun 1/18

1:24 pm-10:24 pm

1 stop6h 00m

$391

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Thu 1/1

6:11 pm-10:25 pm

1 stop7h 14m

Ontario

Sat 1/10

5:05 am-2:26 pm

1 stop6h 21m

$420

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Thu 2/5

5:35 am-12:47 pm

2 stops10h 12m

Ontario

Sat 2/14

5:00 am-2:19 pm

1 stop6h 19m

$425

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Mon 1/12

9:00 am-5:43 pm

2 stops11h 43m

Ontario

Sat 1/17

1:24 pm-10:24 pm

1 stop6h 00m

$425

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Tue 6/9

5:45 pm-10:09 pm

1 stop7h 24m

Ontario

Sat 6/13

12:00 pm-11:59 pm

1 stop8h 59m

$437

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/10

Showing 1-10 of 20 results
1
2

Compare providers for flights from Louisville to Ontario

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 Louisville to Ontario in December.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
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 Louisville-Ontario flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Louisville-Ontario flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Louisville-Ontario flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Louisville-Ontario 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 Louisville-Ontario 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 Louisville to Ontario

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

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

Currently, May is the cheapest month in which you can book a flight from Louisville to Ontario (average of $93). Flying from Louisville to Ontario in April is currently the most expensive (average of $166). 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 SDF to ONT?

Find hourly flight availability from Louisville to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated December 12, 2025.

When flying from Louisville to Ontario, the time of day you fly usually plays a role in the price. Save by searching for a flight in the evening, which can drop the price by up to 37% versus a flight at noon.

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated December 12, 2025.
Get a feel of what it's like to fly with Southwest, Delta, and United Airlines from Louisville to Ontario by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
7.9
Good
4,253 reviews

Food

7.0

Comfort

8.0

Crew

8.6

Boarding

8.1

Entertainment

7.5

Overall

7.9

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
7.9
Good
4,253 reviews
Southwest
7.9
Good
4,253 reviews

Food

7.0

Comfort

8.0

Crew

8.6

Boarding

8.1

Entertainment

7.5

Overall

7.9

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
8,008 reviews
Southwest
7.9
Good
4,253 reviews

Food

7.0

Comfort

8.0

Crew

8.6

Boarding

8.1

Entertainment

7.5

Overall

7.9

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
9,095 reviews
Southwest
7.9
Good
4,253 reviews

Food

7.0

Comfort

8.0

Crew

8.6

Boarding

8.1

Entertainment

7.5

Overall

7.9

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
11,050 reviews
Southwest
7.9
Good
4,253 reviews

Food

7.0

Comfort

8.0

Crew

8.6

Boarding

8.1

Entertainment

7.5

Overall

7.9

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 Louisville to Ontario. 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 Louisville to Ontario?

    Delta can get you from Louisville to Ontario in just under 8h 28m. Your travel time can differ by up to . Airlines will cover a distance of 1791 mi.

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

    American Airlines, at $268, was found to be the cheapest airline from Louisville to Ontario.Alternate airlines to your destination round-trip include Delta and Southwest. American Airlines is currently priced 41% below the average price you’ll pay for this route.

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

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

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

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

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

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

    Currently, May is the cheapest month in which you can book a flight from Louisville to Ontario (average of $93). Flying from Louisville to Ontario in April is currently the most expensive (average of $166). 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

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Top 4 airlines flying from Louisville to Ontario

Discover the top 4 airlines that operate flights from Louisville to Ontario. 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 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$268Average$434FlexibilityNo cancel feeOn-time71%
DeltaCheapest$288Average$403FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$302Average$385FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$344Average$606FlexibilityNo cancel feeOn-time69%

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