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Ontario

$99+ Cheap flights from Oakland, CA to Ontario (OAK - 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 5/27. Fares are subject to change and may not be available on all flights or dates of travel.
OAK — ONT
Jun 3 — Jun 101
Wed 6/3
Wed 6/10
1 adult, Economy
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1. Tell us where you want to go

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Cheapflights Tip: The best prices from Oakland to Ontario are usually found in August or October, booked 84 days in advance, depart on a Tuesday or Thursday and return on a Saturday

Cheap flight deals from Oakland to Ontario

Cheapest flights from Oakland to Ontario
Explore the most affordable flight options available from Oakland to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on May 4, 2026.

This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/1011:05 am
OAK
-
ONT
Nonstop1h 20m
Southwest
Wed 6/104:05 pm
ONT
-
OAK
Nonstop1h 20m
Southwest
Deal found 4/30$197
This Southwest deal was found by Cheapflights users on 5/3. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/28:50 pm
OAK
-
ONT
Nonstop1h 20m
Southwest
Tue 6/910:10 am
ONT
-
OAK
1 stop6h 40m
Southwest
Deal found 5/3$207
This Southwest deal was found by Cheapflights users on 4/29. 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.
Wed 5/206:00 am
OAK
-
ONT
Nonstop1h 20m
Southwest
Thu 5/218:25 pm
ONT
-
OAK
Nonstop1h 20m
Southwest
Deal found 4/29$209
This Southwest deal was found by Cheapflights users on 5/3. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/235:15 am
OAK
-
ONT
1 stop4h 00m
Southwest
Tue 6/236:35 pm
ONT
-
OAK
1 stop4h 45m
Southwest
Deal found 5/3$217
This Southwest deal was found by Cheapflights users on 5/3. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/263:45 pm
OAK
-
ONT
Nonstop1h 20m
Southwest
Thu 5/286:00 pm
ONT
-
OAK
1 stop6h 05m
Southwest
Deal found 5/3$219
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/2810:50 am
OAK
-
ONT
Nonstop1h 20m
Southwest
Thu 5/283:35 pm
ONT
-
OAK
Nonstop1h 20m
Southwest
Deal found 4/30$221
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/3012:40 pm
OAK
-
ONT
2 stops6h 40m
Southwest
Tue 6/211:05 am
ONT
-
OAK
Nonstop1h 25m
Southwest
Deal found 4/30$224
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/166:05 am
OAK
-
ONT
Nonstop1h 25m
Southwest
Wed 6/176:35 pm
ONT
-
OAK
1 stop3h 50m
Southwest
Deal found 4/30$228
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/18:00 pm
OAK
-
ONT
Nonstop1h 20m
Southwest
Wed 6/106:35 pm
ONT
-
OAK
1 stop4h 45m
Southwest
Deal found 4/30$231

Find flight deals from Oakland to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from Oakland (OAK) 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 May 4, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$197
(Southwest)

One-way from

$99
(Southwest)

Popular in

February

Cheapest in

August

Average price

$238

Good round-trip deal

$257 or less

Good one-way deal

$154 or less
Provider with most accurate pricing for Oakland-Ontario flight deals.
Search Deals
Provider most trusted by Cheapflights users for Oakland-Ontario flights.
Search Deals
From Oakland to Ontario
Search Deals
One-way flight from Oakland to Ontario
Search Deals
Highest demand for flights based on searches. 19% potential increase in price ($68 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($12 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in May 2026
Search Deals
Price to beat on a round-trip flight from Oakland to Ontario.
Search Deals
Price to beat on a one-way flight from Oakland to Ontario.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Oakland 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 May 4, 2026.
Use the filters below to find and compare flights from Oakland to Ontario that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OaklandOntario

OAK - ONT

OAKONT

Oakland

Fri 6/19

2:55 pm-10:35 pm

1 stop7h 40m

Ontario

Tue 6/23

10:20 am-11:40 am

Nonstop1h 20m

$258

OaklandOntario

OAK - ONT

OAKONT

Oakland

Tue 6/16

5:15 am-9:15 am

1 stop4h 00m

Ontario

Sat 6/20

5:30 am-12:40 pm

2 stops7h 10m

$294
Quickest round-trip

OaklandOntario

OAK - ONT

OAKONT

Oakland

Fri 5/29

4:00 pm-5:20 pm

Nonstop1h 20m

Ontario

Fri 6/5

4:00 pm-5:15 pm

Nonstop1h 15m

$299

OaklandOntario

OAK - ONT

OAKONT

Oakland

Fri 5/15

8:00 pm-9:20 pm

Nonstop1h 20m

Ontario

Sun 5/17

6:00 am-7:20 am

Nonstop1h 20m

$379

OaklandOntario

OAK - ONT

OAKONT

Oakland

Tue 6/2

7:00 am-3:09 pm

1 stop8h 09m

Ontario

Tue 6/2

5:57 pm-8:55 am

1 stop14h 58m

$393

OaklandOntario

OAK - ONT

OAKONT

Oakland

Sun 5/31

3:00 pm-8:35 pm

2 stops5h 35m

Ontario

Sun 6/7

4:50 pm-10:15 pm

2 stops5h 25m

$412

OaklandOntario

OAK - ONT

OAKONT

Oakland

Mon 5/18

5:15 am-10:55 am

1 stop5h 40m

Ontario

Mon 5/18

12:40 pm-7:55 pm

2 stops7h 15m

$443

OaklandOntario

OAK - ONT

OAKONT

Oakland

Wed 5/13

4:10 pm-9:45 pm

2 stops5h 35m

Ontario

Fri 5/15

6:00 pm-12:05 am

1 stop6h 05m

$486

OaklandOntario

OAK - ONT

OAKONT

Oakland

Sat 6/6

7:00 am-5:17 pm

2 stops10h 17m

Ontario

Tue 6/9

11:15 am-11:59 pm

2 stops12h 44m

$518
Cheapest one-way
Quickest one-way

OaklandOntario

OAK - ONT

OAKONT

Oakland

Mon 6/8

3:15 pm-4:35 pm

Nonstop1h 20m

$111

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/30

Showing 1-10 of 18 resultsSorted by cheapest first
1
2

Compare providers for flights from Oakland 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 Oakland to Ontario in May.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice 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 Oakland, California-Ontario flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Oakland, California-Ontario flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Oakland, California-Ontario flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Oakland, California-Ontario flights, Cheapflights users trust FlightHub the most. FlightHub 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 Oakland, California-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 Oakland to Ontario

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

How far ahead should I book a flight from Oakland, California to Ontario?

To ensure you get the cheapest price possible for a flight from Oakland, California to Ontario, you should look to book at least 83 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from Oakland, California to Ontario?

Currently, August is the cheapest month in which you can book a flight from Oakland, California to Ontario (average of $205). Flying from Oakland, California to Ontario in February is currently the most expensive (average of $411). 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 OAK to ONT?

Find hourly flight availability from Oakland 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 May 4, 2026.

A simple way to save on the total cost of your ticket is to fly from Oakland, California to Ontario in the evening. If you’re flexible enough to do this you can expect to save up to 16% on your trip compared to booking a flight at noon.

What is the cheapest day to fly from Oakland, California to Ontario?

Use this chart to determine the cheapest time to fly round-trip from Oakland to Ontario. Price data was last updated on May 2, 2026.

Travelers seeking maximum savings on their Oakland, California to Ontario flight should consider departing on Sunday evenings when fares are most often at their lowest. Tuesday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

How much does it cost to fly round-trip from Oakland, California to Ontario?

The best insider tips for Oakland to Ontario flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your Oakland to Ontario trip
Our travel experts
Bill Fink

Bill Fink

Expert on ONT and OAK

Bill is an award-winning travel writer with extensive credits covering airlines and the aviation industry for publications including AARP, AFAR, The Points Guy and Yahoo. Based in Portland, Oregon, Bill has traveled to more than 75 countries - and been late for his flight in most of them. He once achieved top-level frequent flier status for all of American, Delta and United Airlines during a single year.

Read more

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 May 4, 2026.
Get a feel of what it's like to fly with Southwest,United Airlines, andFrontier from Oakland 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
4,307 reviews

Crew

8.6

Food

7.0

Entertainment

7.5

Comfort

8.0

Boarding

8.1

Overall

7.9

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
Southwest
7.9
Good
4,307 reviews
Southwest
7.9
Good
4,307 reviews

Crew

8.6

Food

7.0

Entertainment

7.5

Comfort

8.0

Boarding

8.1

Overall

7.9

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
United Airlines
7.4
Good
9,680 reviews
Southwest
7.9
Good
4,307 reviews

Crew

8.6

Food

7.0

Entertainment

7.5

Comfort

8.0

Boarding

8.1

Overall

7.9

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
Frontier
5.6
Fair
2,965 reviews
Southwest
7.9
Good
4,307 reviews

Crew

8.6

Food

7.0

Entertainment

7.5

Comfort

8.0

Boarding

8.1

Overall

7.9

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.

Related info for your journey

Find useful and relevant information for your journey from Oakland to Ontario. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airports do I use to fly from Oakland to Ontario?

    If you book a flight from Oakland to Ontario, you will be flying from Oakland to Ontario. Flights to Ontario (ONT) from Oakland (OAK) take 1h 20m for a nonstop flight. There are 2 flights from Oakland to Ontario per day from 3 airlines.

  • How popular is this Oakland, California to Ontario flight route?

    Within the past month, 19 users have taken a look at flights from Oakland to Ontario.

  • How long is the flight from Oakland, California to Ontario?

    There are many flights that can get you from Oakland, California to Ontario in 7h 40m. Fly via Southwest to get the fastest option. There are 361 mi between Oakland, California and Ontario.

  • What are the cheapest airlines flying from Oakland, California to Ontario round-trip?

    Our cheapest airline available from Oakland, California to Ontario is Frontier. Our recent data shows that you can find tickets from as low as $27 on this airline. Additional options worth looking into are United Airlines and Southwest, starting at $68 and $124 round-trip. Users have found that Frontier is 90% cheaper than the other options available to this destination.

  • What are the cheapest airlines to fly from Oakland, California to Ontario one-way?

    The cheapest airlines for a one-way flight from Oakland, California to Ontario are Frontier ($33), Southwest ($48), and United Airlines ($58).

  • What are the cheapest flights from Oakland, California to Ontario?

    Looking for the cheapest flight from Oakland, California to Ontario? While on average our users pay $262, our data indicates the cheapest price to be $110. The most popular route (Oakland - Ontario), is priced around $197.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Oakland 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 Oakland, California to Ontario?

    Currently, August is the cheapest month in which you can book a flight from Oakland, California to Ontario (average of $205). Flying from Oakland, California to Ontario in February is currently the most expensive (average of $411). 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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Alternative routes for Oakland to Ontario

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Top 3 airlines flying from Oakland to Ontario

Discover the top 3 airlines that operate flights from Oakland 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 May 4, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$27Average$126FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$68Average$148FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$124Average$285FlexibilityNo cancel feeOn-time63%

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