HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Ontario

$149+ 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 8/18. Fares are subject to change and may not be available on all flights or dates of travel.
SDF — ONT
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Louisville to Ontario 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 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 June 12, 2025.

Round-trip from

$297
(Southwest)

One-way from

$149
(Delta)

Popular in

January

Cheapest in

August

Average price

$406
From Louisville Intl to Ontario
Search Deals
One-way flight from Louisville Intl to Ontario
Search Deals
Highest demand for flights based on searches. 22% potential increase in price ($137 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease ($29 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in June 2025
Search Deals

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 June 12, 2025.

This Southwest deal was found by Cheapflights users on 6/10. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/105:30 amSDF - ONT
1 stop9h 05mSouthwest
Wed 9/242:10 pmONT - SDF
1 stop7h 15mSouthwest
Deal found 6/10$297
This American Airlines deal was found by Cheapflights users on 6/11. 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 9/107:45 amSDF - ONT
2 stops11h 20mAmerican Airlines
Wed 9/2412:46 pmONT - SDF
1 stop7h 36mAmerican Airlines
Deal found 6/11$302
This Delta deal was found by Cheapflights users on 6/12. 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 9/187:00 amSDF - ONT
1 stop7h 24mDelta
Mon 9/2210:59 pmONT - SDF
1 stop6h 49mDelta
Deal found 6/12$328
This United Airlines deal was found by Cheapflights users on 6/9. 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 8/283:30 pmSDF - ONT
1 stop8h 13mUnited Airlines
Tue 9/25:10 amONT - SDF
1 stop6h 18mUnited Airlines
Deal found 6/9$382
This Alaska Airlines deal was found by Cheapflights users on 6/11. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/292:33 pmSDF - ONT
2 stops12h 40mAlaska Airlines
Sun 8/36:58 pmONT - SDF
2 stops11h 32mAlaska Airlines
Deal found 6/11$597

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 June 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

Wed 9/10

5:30 am-11:35 am

1 stop9h 05m

Ontario

Wed 9/24

2:10 pm-12:25 am

1 stop7h 15m

$297

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Wed 9/10

7:45 am-4:05 pm

2 stops11h 20m

Ontario

Wed 9/24

12:46 pm-11:22 pm

1 stop7h 36m

$302

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Thu 9/18

7:00 am-11:24 am

1 stop7h 24m

Ontario

Mon 9/22

10:59 pm-8:48 am

1 stop6h 49m

$328

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Thu 8/28

3:30 pm-8:43 pm

1 stop8h 13m

Ontario

Tue 9/2

5:10 am-2:28 pm

1 stop6h 18m

$382

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Tue 7/29

2:33 pm-12:13 am

2 stops12h 40m

Ontario

Sun 8/3

6:58 pm-9:30 am

2 stops11h 32m

$597

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Mon 8/18

5:53 pm-10:20 pm

1 stop7h 27m

$149

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Sat 9/6

10:00 am-6:11 pm

2 stops11h 11m

$163

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Wed 7/9

3:25 pm-8:54 pm

1 stop8h 29m

$235

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Fri 7/25

10:45 am-3:55 pm

2 stops8h 10m

$255

LouisvilleOntario

SDF - ONT

SDFONT

Louisville Intl

Sat 7/12

12:38 pm-11:59 pm

2 stops14h 21m

$339

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/10

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 June 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 38% versus a flight at noon.

Rainfall in Ontario by month

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

In terms of precipitation, rainfall in Ontario ranges from 0.1 - 3.4 inches per month. February is typically the wettest month, when rainfall can reach 3.4 in. June is typically the driest time to visit Ontario when rainfall is around 0.1 in.

Temperature in Ontario by month

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

If weather is an important factor for your trip to Ontario, use this chart to help with planning. For those seeking warmer temperatures, August 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 December, when temperatures are typically at their lowest (around 53.6 F).

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 June 12, 2025.
Peruse reviews from past customers who have flown with Alaska Airlines, Southwest and Delta from Louisville to Ontario to help guide your decision. You can also see how each airline compares 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

Entertainment

7.1

Overall

8.0

Food

7.1

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

Entertainment

7.1

Overall

8.0

Food

7.1

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
4,287 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Entertainment

7.1

Overall

8.0

Food

7.1

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
7,946 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Entertainment

7.1

Overall

8.0

Food

7.1

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
8,790 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Comfort

7.8

Entertainment

7.1

Overall

8.0

Food

7.1

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

Entertainment

7.1

Overall

8.0

Food

7.1

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?

    Southwest, at $297, was found to be the cheapest airline from Louisville to Ontario.Alternate airlines to your destination round-trip include American Airlines and Delta. Southwest is currently priced 38% below the average price you’ll pay for this route.

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

    $149 is the cheapest one-way deal found within the past few days, from Delta. You may also be able to find cheap deals on American Airlines and United Airlines, with prices starting from $163 and $235, 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

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 Louisville to Ontario

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

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 June 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$257Average$506FlexibilityNo cancel feeOn-time69%
DeltaCheapest$288Average$403FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$306Average$445FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$342Average$476FlexibilityNo 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.