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$163+ 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 9/27. Fares are subject to change and may not be available on all flights or dates of travel.
SDF — ONT
Aug 4 — Aug 111
Mon 8/4
Mon 8/11
1 adult, Economy
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Cheap 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 July 30, 2025.

Round-trip from

$325
(American Airlines)

One-way from

$163
(American Airlines)

Popular in

January

Cheapest in

April

Average price

$458
From Louisville Intl to Ontario
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One-way flight from Louisville Intl to Ontario
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Highest demand for flights based on searches. 20% potential increase in price ($124 potential increase over avg. RT price).
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Cheapest flight prices on average. 5% potential price decrease ($28 potential savings vs. average RT price).
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Average for round-trip flights in July 2025
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Find 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 July 30, 2025.

This American Airlines deal was found by Cheapflights users on 7/30. 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.
Wed 9/106:44 pmSDF - ONT
1 stop6h 49mAmerican Airlines
Wed 9/2412:47 pmONT - SDF
1 stop7h 53mAmerican Airlines
Deal found 7/30$325
This United Airlines deal was found by Cheapflights users on 7/30. 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 9/29:31 amSDF - ONT
1 stop6h 01mUnited Airlines
Thu 9/45:10 amONT - SDF
1 stop6h 18mUnited Airlines
Deal found 7/30$326
This Delta deal was found by Cheapflights users on 7/28. 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 9/1010:24 amSDF - ONT
2 stops11h 47mDelta
Wed 9/2410:00 pmONT - SDF
2 stops8h 46mDelta
Deal found 7/28$335
This Southwest deal was found by Cheapflights users on 7/29. 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 9/185:20 pmSDF - ONT
1 stop8h 25mSouthwest
Sun 9/211:25 pmONT - SDF
2 stops9h 30mSouthwest
Deal found 7/29$412
This Alaska Airlines deal was found by Cheapflights users on 7/29. 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.
Thu 9/117:00 amSDF - ONT
2 stops14h 47mAlaska Airlines
Sat 9/137:10 amONT - SDF
2 stops13h 30mAlaska Airlines
Deal found 7/29$547

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 July 30, 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

Wed 9/10

6:44 pm-10:33 pm

1 stop6h 49m

Ontario

Wed 9/24

12:47 pm-11:40 pm

1 stop7h 53m

$325

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Tue 9/2

9:31 am-12:32 pm

1 stop6h 01m

Ontario

Thu 9/4

5:10 am-2:28 pm

1 stop6h 18m

$326

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Wed 9/10

10:24 am-7:11 pm

2 stops11h 47m

Ontario

Wed 9/24

10:00 pm-9:46 am

2 stops8h 46m

$335

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Thu 9/18

5:20 pm-10:45 pm

1 stop8h 25m

Ontario

Sun 9/21

1:25 pm-1:55 am

2 stops9h 30m

$412

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Thu 9/11

7:00 am-6:47 pm

2 stops14h 47m

Ontario

Sat 9/13

7:10 am-11:40 pm

2 stops13h 30m

$547

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Sat 9/27

6:44 pm-10:33 pm

1 stop6h 49m

$163

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Sat 9/27

6:00 am-12:17 pm

2 stops9h 17m

$168

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Thu 9/11

7:10 pm-10:30 pm

1 stop6h 20m

$169

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Sat 10/18

3:30 pm-8:24 pm

1 stop7h 54m

$208

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Fri 9/12

7:00 am-6:47 pm

2 stops14h 47m

$289

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/29

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, August is the cheapest month in which you can book a flight from Louisville to Ontario (average of $246). Flying from Louisville to Ontario in March is currently the most expensive (average of $328). 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 July 30, 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 38% 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 July 30, 2025.
Get a feel of what it's like to fly with Alaska Airlines, Southwest, and Delta 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.
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Food

7.1

Entertainment

7.1

Overall

8.0

Crew

8.5

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
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Food

7.1

Entertainment

7.1

Overall

8.0

Crew

8.5

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
4,241 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Food

7.1

Entertainment

7.1

Overall

8.0

Crew

8.5

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
7,980 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Food

7.1

Entertainment

7.1

Overall

8.0

Crew

8.5

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
8,896 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Food

7.1

Entertainment

7.1

Overall

8.0

Crew

8.5

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
10,000 reviews

Boarding

8.1

Comfort

7.8

Food

7.1

Entertainment

7.1

Overall

8.0

Crew

8.5

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 Louisville to Ontario. 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 Louisville to Ontario round-trip?

    American Airlines, at $325, was found to be the cheapest airline from Louisville to Ontario.Alternate airlines to your destination round-trip include United Airlines and Delta. American Airlines is currently priced 34% below the average price you’ll pay for this route.

  • What are the cheapest airlines to fly from Louisville to Ontario one-way?

    $163 is the cheapest one-way deal found within the past few days, from American Airlines. You may also be able to find cheap deals on Delta and United Airlines, with prices starting from $168 and $208, respectively.

  • 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, August is the cheapest month in which you can book a flight from Louisville to Ontario (average of $246). Flying from Louisville to Ontario in March is currently the most expensive (average of $328). 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 July 30, 2025.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$257Average$606FlexibilityNo cancel feeOn-time69%
DeltaCheapest$288Average$403FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$315Average$466FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$361Average$516FlexibilityNo cancel feeOn-time71%

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