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Cheap flights from Ontario to San Diego from $58

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ontario to San Diego departing on 9/28. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

Find the cheapest flights from Ontario to San Diego

Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
6:15 am - 11:51 pmONT  Ontario-SAN San Diego
17h 36m1 stop Denver Intl
Frontier Logo
10:28 am - 7:36 pmSAN  San Diego-ONT Ontario
9h 08m1 stop San Francisco
$135Frontier
Fri, Sep 11 - Mon, Sep 14
Frontier Logo
8:48 am - 2:50 pmONT  Ontario-SAN San Diego
6h 02m1 stop San Francisco
Frontier Logo
7:04 pm - 10:30 amSAN  San Diego-ONT Ontario
39h 26m2 stops Phoenix Sky Harbor Intl Denver Intl
$160Frontier
Sun, Sep 6 - Wed, Sep 9
Frontier Logo
12:07 pm - 6:19 pmONT  Ontario-SAN San Diego
6h 12m1 stop San Francisco
Frontier Logo
5:54 pm - 7:04 amSAN  San Diego-ONT Ontario
13h 10m1 stop Las Vegas Harry Reid Intl
$179Frontier
Mon, Sep 14 - Wed, Sep 16
Frontier Logo
12:07 pm - 6:19 pmONT  Ontario-SAN San Diego
6h 12m1 stop San Francisco
Frontier Logo
7:04 pm - 11:22 amSAN  San Diego-ONT Ontario
16h 18m2 stops Phoenix Sky Harbor Intl Las Vegas Harry Reid Intl
$180Frontier
Mon, Sep 14 - Wed, Sep 16
Frontier Logo
8:48 am - 2:50 pmONT  Ontario-SAN San Diego
6h 02m1 stop San Francisco
Frontier Logo
5:54 pm - 11:22 amSAN  San Diego-ONT Ontario
17h 28m1 stop Las Vegas Harry Reid Intl
$190Frontier
Sun, Sep 6 - Wed, Sep 9
Frontier Logo
10:04 am - 4:59 pmONT  Ontario-SAN San Diego
6h 55m1 stop Las Vegas Harry Reid Intl
Frontier Logo
9:03 pm - 9:09 amSAN  San Diego-ONT Ontario
12h 06m1 stop Las Vegas Harry Reid Intl
$192Frontier
Sat, Sep 26 - Mon, Sep 28
Frontier Logo
8:48 am - 2:50 pmONT  Ontario-SAN San Diego
6h 02m1 stop San Francisco
Frontier Logo
6:25 am - 11:50 pmSAN  San Diego-ONT Ontario
17h 25m2 stops Phoenix Sky Harbor Intl Denver Intl
$201Frontier
Sun, Sep 6 - Tue, Sep 8
Frontier Logo
7:56 pm - 9:05 amONT  Ontario-SAN San Diego
13h 09m1 stop Denver Intl
Frontier Logo
5:54 pm - 7:04 amSAN  San Diego-ONT Ontario
13h 10m1 stop Las Vegas Harry Reid Intl
$204Frontier
Sat, Sep 5 - Sat, Sep 12
Frontier Logo
10:04 am - 4:59 pmONT  Ontario-SAN San Diego
6h 55m1 stop Las Vegas Harry Reid Intl
Frontier Logo
5:54 pm - 4:59 pmSAN  San Diego-ONT Ontario
23h 05m1 stop Las Vegas Harry Reid Intl
$205Frontier
Wed, Sep 9 - Tue, Sep 15
Frontier Logo
10:04 am - 6:19 pmONT  Ontario-SAN San Diego
8h 15m2 stops Las Vegas Harry Reid Intl San Francisco
Frontier Logo
9:03 pm - 9:09 amSAN  San Diego-ONT Ontario
12h 06m1 stop Las Vegas Harry Reid Intl
$208Frontier
Sat, Sep 26 - Mon, Sep 28

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Frontier flights from Ontario to San Diego

Our best Frontier deals on Ontario to San Diego flight tickets
Frontier
Sep 11
ONT6:15 amOntario
17h 36m
1 stop
SAN11:51 pmSan Diego
Sep 14
SAN10:28 amSan Diego
9h 08m
1 stop
ONT7:36 pmOntario
$135
Frontier
Sep 6
ONT8:48 amOntario
6h 02m
1 stop
SAN2:50 pmSan Diego
Sep 9
SAN7:04 pmSan Diego
39h 26m
2 stops
ONT10:30 amOntario
$160
Frontier
Sep 14
ONT12:07 pmOntario
6h 12m
1 stop
SAN6:19 pmSan Diego
Sep 16
SAN5:54 pmSan Diego
13h 10m
1 stop
ONT7:04 amOntario
$179

Alaska Airlines flights from Ontario to San Diego

Our best Alaska Airlines deals on Ontario to San Diego flight tickets
Alaska Airlines
Sep 11
ONT4:27 pmOntario
4h 09m
1 stop
SAN8:36 pmSan Diego
Sep 21
SAN7:57 amSan Diego
7h 50m
1 stop
ONT3:47 pmOntario
$255
Alaska Airlines
Sep 29
ONT4:27 pmOntario
15h 38m
1 stop
SAN8:05 amSan Diego
Oct 3
SAN12:48 pmSan Diego
4h 17m
1 stop
ONT5:05 pmOntario
$264
Alaska Airlines
Sep 14
ONT4:27 pmOntario
4h 09m
1 stop
SAN8:36 pmSan Diego
Sep 21
SAN7:57 amSan Diego
7h 50m
1 stop
ONT3:47 pmOntario
$265

momondo Fare Finder

 
Customize your flight search to find flights from Ontario to San Diego 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, momondo users made 832,500 searches. Data last updated August 13, 2026.
Use the filters below to find and compare flights from Ontario to San Diego that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioSan Diego

ONT Ontario - SAN San Diego

ONTSAN

Ontario

Fri 9/11

6:15 am-11:51 pm

1 stop17h 36m

San Diego

Mon 9/14

10:28 am-7:36 pm

1 stop9h 08m

$135

OntarioSan Diego

ONT Ontario - SAN San Diego

ONTSAN

Ontario

Sun 9/6

8:48 am-2:50 pm

1 stop6h 02m

San Diego

Wed 9/9

7:04 pm-10:30 am

2 stops39h 26m

$160

OntarioSan Diego

ONT Ontario - SAN San Diego

ONTSAN

Ontario

Mon 9/14

12:07 pm-6:19 pm

1 stop6h 12m

San Diego

Wed 9/16

5:54 pm-7:04 am

1 stop13h 10m

$179

OntarioSan Diego

ONT Ontario - SAN San Diego

ONTSAN

Ontario

Mon 9/14

12:07 pm-6:19 pm

1 stop6h 12m

San Diego

Wed 9/16

7:04 pm-11:22 am

2 stops16h 18m

$180

OntarioSan Diego

ONT Ontario - SAN San Diego

ONTSAN

Ontario

Sun 9/6

8:48 am-2:50 pm

1 stop6h 02m

San Diego

Wed 9/9

5:54 pm-11:22 am

1 stop17h 28m

$190
Quickest round-trip

OntarioSan Diego

ONT Ontario - SAN San Diego

ONTSAN

Ontario

Sat 9/26

10:04 am-4:59 pm

1 stop6h 55m

San Diego

Mon 9/28

9:03 pm-9:09 am

1 stop12h 06m

$192

OntarioSan Diego

ONT Ontario - SAN San Diego

ONTSAN

Ontario

Sun 9/6

8:48 am-2:50 pm

1 stop6h 02m

San Diego

Tue 9/8

6:25 am-11:50 pm

2 stops17h 25m

$201

OntarioSan Diego

ONT Ontario - SAN San Diego

ONTSAN

Ontario

Sat 9/5

7:56 pm-9:05 am

1 stop13h 09m

San Diego

Sat 9/12

5:54 pm-7:04 am

1 stop13h 10m

$204

OntarioSan Diego

ONT Ontario - SAN San Diego

ONTSAN

Ontario

Wed 9/9

10:04 am-4:59 pm

1 stop6h 55m

San Diego

Tue 9/15

5:54 pm-4:59 pm

1 stop23h 05m

$205

OntarioSan Diego

ONT Ontario - SAN San Diego

ONTSAN

Ontario

Sat 9/26

10:04 am-6:19 pm

2 stops8h 15m

San Diego

Mon 9/28

9:03 pm-9:09 am

1 stop12h 06m

$208

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to San Diego from

How to get the cheapest flight ticket from Ontario to San Diego

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest day to depart on your flight to San Diego?

The cheapest day to depart from Ontario to San Diego is on a Thursday. Travelers who choose to depart for San Diego on a Thursday will often find tickets for as low as $239. If your travel schedule is flexible, try to avoid departing on a Monday because tickets tend to average around $467. These prices are subject to change though, so be sure to set up a Price Alert for flights to San Diego.

What is the cheapest time of day to depart on your flight to San Diego?

The cheapest time of day to fly to San Diego is in the morning when flights can be purchased for as low as $252. Flights at noon are often more expensive with an average ticket price of $309.

When to book flights from Ontario to San Diego

Are you open to changing your travel dates? Check out the ideal times to fly from Ontario to San Diego according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Ontario to San Diego (ONT to SAN) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Ontario to San Diego

Fastest flight time

3h 20m

Direct flights

None
The fastest flight from Ontario to San Diego takes 3h 20m
There are no direct flights from Ontario to San Diego. There are no popular flight routes from Ontario to San Diego.
Search flight deals

Frequently asked questions about flying from Ontario to San Diego

  • How far is Ontario to San Diego by plane?

    A flight from Ontario to San Diego will travel around 97.3 mi. By plane, this route typically takes 3h 20m.

  • When did momondo last update prices for flights from Ontario Airport to San Diego Airport?

    Prices for flights from Ontario Airport to San Diego Airport are updated daily.

  • How old do you have to be to fly from Ontario Airport to San Diego Airport?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Ontario Airport to San Diego Airport.

  • What documentation or ID do you need to fly to San Diego Airport?

    The necessary travel and health documents for your San Diego Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

Traveling to a place near San Diego?

Book flights to San Diego if you plan to visit one of these locations
Chula Vista
Coronado
El Cajon
National City
Julian
La Mesa
Poway
San Ysidro
Imperial Beach
Santee
Borrego Springs
Lemon Grove
Alpine

Why use momondo?

Why should I use momondo to find a flight deal from Ontario to San Diego?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Ontario to San Diego. momondo saves you time and could save you money on your trip.

Can I find flights from Ontario to San Diego with flexible booking policies on momondo?

Yes. momondo allows you to filter the results for Ontario to San Diego flights to just show those with flexible booking policies.

How can momondo help me find flights from Ontario to San Diego?

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to San Diego from Ontario.

I’m not ready to book a flight from Ontario to San Diego right now. Can momondo alert me if prices change?

Of course. momondo tracks the price of Ontario to San Diego flights. All you need is a valid email address and we will do the rest; it is that quick and easy.

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