Cheap flights from Ontario to San Diego from $79

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.
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0 bags

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Cheap round-trip flights

Multiple Airlines Logo
8:00 am - 12:31 pmONT-SAN
4h 31m1 stop
Multiple Airlines Logo
6:15 am - 12:43 pmSAN-ONT
6h 28m1 stop
$144Multiple Airlines
Find Deal
Tue, Sep 30 - Sat, Oct 4
Frontier Logo
6:53 am - 1:28 pmONT-SAN
6h 35m1 stop
Frontier Logo
6:36 am - 11:57 pmSAN-ONT
17h 21m1 stop
$154Frontier
Find Deal
Tue, Nov 18 - Thu, Nov 20
Frontier Logo
10:47 pm - 9:20 pmONT-SAN
22h 33m1 stop
Frontier Logo
5:28 pm - 12:12 amSAN-ONT
6h 44m1 stop
$161Frontier
Find Deal
Mon, Oct 13 - Mon, Oct 20
Multiple Airlines Logo
8:00 am - 7:29 amONT-SAN
23h 29m1 stop
Multiple Airlines Logo
12:33 pm - 7:17 amSAN-ONT
18h 44m1 stop
$169Multiple Airlines
Find Deal
Wed, Oct 1 - Sun, Oct 5
Frontier Logo
8:00 am - 9:20 pmONT-SAN
13h 20m1 stop
Frontier Logo
8:00 am - 8:42 pmSAN-ONT
12h 42m1 stop
$171Frontier
Find Deal
Wed, Oct 15 - Wed, Oct 22
United Airlines Logo
6:36 pm - 7:56 amONT-SAN
13h 20m1 stop
United Airlines Logo
9:54 am - 10:51 pmSAN-ONT
12h 57m1 stop
$353United Airlines
Find Deal
Mon, Oct 20 - Mon, Oct 27
United Airlines Logo
1:33 pm - 10:49 pmONT-SAN
9h 16m1 stop
United Airlines Logo
11:20 am - 8:44 pmSAN-ONT
9h 24m1 stop
$377United Airlines
Find Deal
Wed, Oct 29 - Sat, Nov 1
Alaska Airlines Logo
1:31 pm - 8:53 pmONT-SAN
7h 22m1 stop
Alaska Airlines Logo
6:09 pm - 11:51 pmSAN-ONT
5h 42m1 stop
$420Alaska Airlines
Find Deal
Wed, Oct 22 - Fri, Oct 24
Alaska Airlines Logo
7:10 am - 5:13 pmONT-SAN
10h 03m1 stop
Alaska Airlines Logo
7:50 pm - 12:37 pmSAN-ONT
16h 47m1 stop
$462Alaska Airlines
Find Deal
Sat, Oct 11 - Sat, Oct 11
American Airlines Logo
7:16 pm - 8:53 amONT-SAN
13h 37m1 stop
American Airlines Logo
9:45 am - 6:16 pmSAN-ONT
8h 31m1 stop
$741American Airlines
Find Deal
Sun, Sep 28 - Sat, Oct 4

Frontier flights from Ontario to San Diego

Our best Frontier deals on Ontario to San Diego flight tickets
Frontier
Nov 18
ONT6:53 amOntario
6h 35m
1 stop
SAN1:28 pmSan Diego
Nov 20
SAN6:36 amSan Diego
17h 21m
1 stop
ONT11:57 pmOntario
Frontier
Oct 13
ONT10:47 pmOntario
22h 33m
1 stop
SAN9:20 pmSan Diego
Oct 20
SAN5:28 pmSan Diego
6h 44m
1 stop
ONT12:12 amOntario
Frontier
Oct 15
ONT8:00 amOntario
13h 20m
1 stop
SAN9:20 pmSan Diego
Oct 22
SAN8:00 amSan Diego
12h 42m
1 stop
ONT8:42 pmOntario

United Airlines flights from Ontario to San Diego

Our best United Airlines deals on Ontario to San Diego flight tickets
United Airlines
Oct 20
ONT6:36 pmOntario
13h 20m
1 stop
SAN7:56 amSan Diego
Oct 27
SAN9:54 amSan Diego
12h 57m
1 stop
ONT10:51 pmOntario
United Airlines
Oct 29
ONT1:33 pmOntario
9h 16m
1 stop
SAN10:49 pmSan Diego
Nov 1
SAN11:20 amSan Diego
9h 24m
1 stop
ONT8:44 pmOntario
United Airlines
Oct 15
ONT6:36 pmOntario
13h 20m
1 stop
SAN7:56 amSan Diego
Oct 16
SAN1:59 pmSan Diego
8h 53m
1 stop
ONT10:52 pmOntario

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 September 17, 2025.
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

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Tue 9/30

8:00 am-12:31 pm

1 stop4h 31m

San Diego

Sat 10/4

6:15 am-12:43 pm

1 stop6h 28m

$144

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Tue 11/18

6:53 am-1:28 pm

1 stop6h 35m

San Diego

Thu 11/20

6:36 am-11:57 pm

1 stop17h 21m

$154

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Mon 10/13

10:47 pm-9:20 pm

1 stop22h 33m

San Diego

Mon 10/20

5:28 pm-12:12 am

1 stop6h 44m

$161

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Wed 10/1

8:00 am-7:29 am

1 stop23h 29m

San Diego

Sun 10/5

12:33 pm-7:17 am

1 stop18h 44m

$169

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Wed 10/15

8:00 am-9:20 pm

1 stop13h 20m

San Diego

Wed 10/22

8:00 am-8:42 pm

1 stop12h 42m

$171

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Mon 10/20

6:36 pm-7:56 am

1 stop13h 20m

San Diego

Mon 10/27

9:54 am-10:51 pm

1 stop12h 57m

$353

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Wed 10/29

1:33 pm-10:49 pm

1 stop9h 16m

San Diego

Sat 11/1

11:20 am-8:44 pm

1 stop9h 24m

$377

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Wed 10/22

1:31 pm-8:53 pm

1 stop7h 22m

San Diego

Fri 10/24

6:09 pm-11:51 pm

1 stop5h 42m

$420

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Sat 10/11

7:10 am-5:13 pm

1 stop10h 03m

San Diego

Sat 10/11

7:50 pm-12:37 pm

1 stop16h 47m

$462

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Sun 9/28

7:16 pm-8:53 am

1 stop13h 37m

San Diego

Sat 10/4

9:45 am-6:16 pm

1 stop8h 31m

$741

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 Tuesday. Travelers who choose to depart for San Diego on a Tuesday will often find tickets for as low as $179. If your travel schedule is flexible, try to avoid departing on a Monday because tickets tend to average around $407. 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 at noon when flights can be purchased for as low as $179. Flights in the afternoon are often more expensive with an average ticket price of $289.

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

Direct flights

None
There are no direct flights from Ontario to San Diego. There are no popular flight routes 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 4h 31m.

  • 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
Coronado
Chula Vista
El Cajon
Julian
La Mesa
National City
Poway
Imperial Beach
San Ysidro
Borrego Springs
Lemon Grove
Alpine
Santee

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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1 adult
Fri 10/17
Fri 10/24

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