HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
San Diego

$72+ Cheap flights from Illinois to San Diego (SAN)

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 10/21. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SAN
Nov 1 — Nov 81
Sat 11/1
Sat 11/8
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Illinois to San Diego 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 Illinois to San Diego

Keep the following information in mind while searching for Illinois to San Diego flight deals. Data was last updated October 2, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$143
(Kiwi.com)

One-way from

$72
(Cheapflightsfares)

Popular in

March

Cheapest in

August

Average price

$285

Good round-trip deal

$180 or less

Good one-way deal

$98 or less
Provider with most accurate pricing for Chicago (CHI)-San Diego flight deals.
Search Deals
Provider most trusted by Cheapflights users for Chicago (CHI)-San Diego flights.
Search Deals
From Illinois to San Diego
Search Deals
One-way flight from Illinois to San Diego
Search Deals
Highest demand for flights based on searches. 13% potential increase in price ($57 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($11 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in October 2025
Search Deals
Price to beat on a round-trip flight from Illinois to San Diego.
Search Deals
Price to beat on a one-way flight from Illinois to San Diego.
Search Deals

Find flight deals from Illinois to San Diego

Cheapest flights from Illinois to San Diego
Explore the most affordable flight options available from Illinois to San Diego. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 2, 2025.

This Kiwi.com deal was found by Cheapflights users on 10/2. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/88:59 pmORD - SAN
Nonstop4h 20mHawaiian Airlines
Sat 11/155:49 pmSAN - ORD
Nonstop4h 10mHawaiian Airlines
Deal found 10/2$143
This Trip.com deal was found by Cheapflights users on 10/1. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/88:59 pmORD - SAN
Nonstop4h 20mAlaska Airlines
Sat 11/155:49 pmSAN - ORD
Nonstop4h 10mAlaska Airlines
Deal found 10/1$144
This Cheapflightsfares deal was found by Cheapflights users on 9/30. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/58:59 pmORD - SAN
Nonstop4h 20mAlaska Airlines
Wed 11/125:49 pmSAN - ORD
Nonstop4h 10mAlaska Airlines
Deal found 9/30$149
This Trip.com deal was found by Cheapflights users on 10/2. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/88:59 pmORD - SAN
Nonstop4h 20mMultiple Airlines
Sat 11/155:49 pmSAN - ORD
Nonstop4h 10mMultiple Airlines
Deal found 10/2$150
This Alaska Airlines deal was found by Cheapflights users on 9/30. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/88:59 pmORD - SAN
Nonstop4h 20mAlaska Airlines
Tue 11/111:41 pmSAN - ORD
Nonstop4h 14mAlaska Airlines
Deal found 9/30$153
This Frontier deal was found by Cheapflights users on 9/29. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/82:57 pmMDW - SAN
1 stop7h 27mFrontier
Mon 11/176:25 amSAN - MDW
1 stop8h 36mFrontier
Deal found 9/29$154
This Frontier deal was found by Cheapflights users on 9/29. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/136:00 amORD - SAN
1 stop7h 17mFrontier
Fri 11/1411:34 amSAN - ORD
1 stop11h 09mFrontier
Deal found 9/29$154
This Mytrip deal was found by Cheapflights users on 10/1. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/82:57 pmMDW - SAN
1 stop7h 27mFrontier
Sat 11/155:28 pmSAN - MDW
1 stop16h 02mFrontier
Deal found 10/1$155
This Flightnetwork deal was found by Cheapflights users on 10/2. 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 Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/87:15 amORD - SAN
1 stop13h 30mFrontier
Sat 11/156:41 amSAN - ORD
1 stop14h 48mFrontier
Deal found 10/2$155
This Booking.com deal was found by Cheapflights users on 9/30. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/3012:30 pmMDW - SAN
1 stop13h 20mFrontier
Wed 11/56:41 amSAN - MDW
1 stop26h 49mFrontier
Deal found 9/30$156
This Booking.com deal was found by Cheapflights users on 9/30. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/25:00 amORD - SAN
1 stop7h 17mFrontier
Fri 11/76:41 amSAN - ORD
1 stop15h 34mFrontier
Deal found 9/30$156
This Cheapflightsfares deal was found by Cheapflights users on 9/30. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/227:52 pmSTL - SAN
1 stop5h 58mFrontier
Sat 10/258:00 amSAN - STL
1 stop5h 56mFrontier
Deal found 9/30$156

Cheapflights Fare Finder

 
Customize your flight search to find flights from Illinois 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, Cheapflights users made 2,558,603 searches. Data last updated October 2, 2025.
Use the filters below to find and compare flights from Illinois to San Diego that are best for you.

Fly from

Illinois

Fly to

San Diego

Route

Depart

Return

Price

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Sat 11/8

8:59 pm-11:19 pm

Nonstop4h 20m

San Diego

Sat 11/15

5:49 pm-11:59 pm

Nonstop4h 10m

$153

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Wed 11/12

9:20 am-11:45 am

Nonstop4h 25m

San Diego

Sat 11/15

5:49 pm-11:59 pm

Nonstop4h 10m

$153

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Sat 11/8

8:59 pm-11:19 pm

Nonstop4h 20m

San Diego

Mon 11/10

5:49 pm-11:59 pm

Nonstop4h 10m

$175

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Wed 11/19

2:54 pm-5:19 pm

Nonstop4h 25m

San Diego

Fri 11/21

5:31 pm-11:32 pm

Nonstop4h 01m

$175

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Tue 11/25

8:20 am-10:46 am

Nonstop4h 26m

San Diego

Wed 12/3

5:53 pm-11:50 pm

Nonstop3h 57m

$175

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Sat 11/8

8:59 pm-11:19 pm

Nonstop4h 20m

San Diego

Sun 11/16

5:49 pm-11:59 pm

Nonstop4h 10m

$175

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Mon 11/24

8:20 am-10:46 am

Nonstop4h 26m

San Diego

Mon 11/24

1:43 pm-7:53 pm

Nonstop4h 10m

$191

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Wed 10/29

2:54 pm-5:19 pm

Nonstop4h 25m

San Diego

Mon 11/3

1:41 pm-7:55 pm

Nonstop4h 14m

$197

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Sun 11/2

8:59 pm-11:19 pm

Nonstop4h 20m

San Diego

Fri 11/7

1:41 pm-7:55 pm

Nonstop4h 14m

$197

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Sat 10/18

1:50 pm-4:05 pm

Nonstop4h 15m

San Diego

Tue 10/21

6:30 am-12:35 pm

Nonstop4h 05m

$198

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/2

Showing 1-10 of 60 results
1
2
3
...
6

Best time to book a flight from Illinois to San Diego

Have a flexible travel schedule? Discover the best time to fly to San Diego from Illinois 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 Illinois to San Diego

What is the cheapest month to book a flight from Illinois to San Diego?

Currently, August is the cheapest month in which you can book a flight from Illinois to San Diego (average of $286). Flying from Illinois to San Diego in March is currently the most expensive (average of $366). 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 IL to SAN?

Find hourly flight availability from Illinois to San Diego. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 2, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Illinois to San Diego as you normally would.

Weekly flight availability from Illinois to San Diego

Explore weekly flight availability from Illinois to San Diego. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated October 2, 2025.

The most flights from USIL to SAN are scheduled on a Wednesday (32 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (18 on average).

Related info for your journey

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

  • What airport do you fly into for flights to San Diego from Illinois?

    Most people fly into San Diego (SAN) if they book a flight to San Diego from Illinois. San Diego is conveniently located just 2.6 mi from San Diego’s city center.

  • How long is the flight from Illinois to San Diego?

    For as low as $198, Alaska Airlines can have you in San Diego from Illinois in 4h 15m. Illinois and San Diego are separated by a distance of 1725 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines to fly from Illinois to San Diego one-way?

    To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $72. Southwest flights start at $77 while deals on Alaska Airlines start at $77 one-way.

  • What are the most popular routes from Illinois to San Diego?

    Most travelers choose Chicago O'Hare Intl - San Diego, Chicago Midway - San Diego or Lambert-St Louis - San Diego when deciding on the best route from Illinois to San Diego.

  • What are the most reliable airlines from Illinois to San Diego?

    Consider Japan Airlines (87%), Alaska Airlines (81%) or American Airlines (79%) when booking your flight. These represent the most reliable airlines when flying from Illinois to San Diego.

  • What are the cheapest flights from Illinois to San Diego?

    The cheapest flight price from Illinois to San Diego is $79. On average you can expect to pay $683. The most popular route, (Chicago O'Hare Intl - San Diego), can usually be booked for $148.

  • Can I find deals for flights from Illinois to San Diego that include hotel bookings?

    Yes. In addition to deals on Illinois to San Diego flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Illinois to San Diego?

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

  • Can I find deals for business class flights from Illinois to San Diego?

    Yes. Cheapflights offers flight deals from Illinois to San Diego 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 Illinois to San Diego?

    Currently, August is the cheapest month in which you can book a flight from Illinois to San Diego (average of $286). Flying from Illinois to San Diego in March is currently the most expensive (average of $366). 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

Traveling to a place near San Diego?

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

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 Illinois to San Diego

See prices for flight routes from nearby airports that may be better suited for you.
John F Kennedy Intl to Los Angeles flights
John F Kennedy Intl to Las Vegas flights
Dallas/Fort Worth to Las Vegas flights
Seattle to Las Vegas flights
Seattle to Los Angeles flights
Dallas/Fort Worth to Los Angeles flights
John F Kennedy Intl to San Francisco flights
O'Hare Intl to Las Vegas flights
Newark to San Francisco flights
Newark to Los Angeles flights
San Francisco to Las Vegas flights
Dulles Intl to Las Vegas flights
LaGuardia to Los Angeles flights
San Francisco to Los Angeles flights
Newark to Las Vegas flights
Los Angeles to Las Vegas flights
Atlanta to Las Vegas flights
Denver to Las Vegas flights
O'Hare Intl to Los Angeles flights
Los Angeles to San Francisco flights
Reagan-National to Las Vegas flights
Seattle to San Francisco flights
Santa Ana to San Francisco flights
Reagan-National to Los Angeles flights
Seattle to Santa Ana flights
Dallas/Fort Worth to San Francisco flights
LaGuardia to Las Vegas flights
Boston to Las Vegas flights
San Francisco to Ontario flights
Burbank to Las Vegas flights
Minneapolis to Las Vegas flights
San Jose to Las Vegas flights
Dulles Intl to Los Angeles flights
Seattle to San Diego flights
Santa Ana to Las Vegas flights
Seattle to Ontario flights
San Jose to Los Angeles flights
Boston to Los Angeles flights
Baltimore to Las Vegas flights
Ontario to San Francisco flights
Atlanta to Los Angeles flights
John F Kennedy Intl to Ontario flights
Orlando to Las Vegas flights
John F Kennedy Intl to San Diego flights
LaGuardia to San Francisco flights
Love Field to Las Vegas flights
San Francisco to Santa Ana flights
Reagan-National to San Francisco flights
Hobby to Las Vegas flights
Austin to Las Vegas flights

Top 8 airlines flying from Illinois to San Diego

Discover the top 8 airlines that operate flights from Illinois to San Diego. 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 October 2, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$93Average$206FlexibilityNo cancel feeOn-time65%
FrontierCheapest$102Average$202FlexibilityNo cancel feeOn-time62%
Alaska AirlinesCheapest$142Average$238FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$159Average$445FlexibilityNo cancel feeOn-time71%
Hawaiian AirlinesCheapest$168Average$240FlexibilityNo cancel feeOn-time85%
SouthwestCheapest$188Average$459FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$189Average$457FlexibilityNo cancel feeOn-time69%
DeltaCheapest$223Average$330FlexibilityNo cancel feeOn-timeN/A

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.