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$59+ 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 4/18. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SAN
Mar 23 — Mar 301
Mon 3/23
Mon 3/30
1 adult, Economy
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Cheap 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 February 21, 2026.

This American Airlines deal was found by Cheapflights users on 2/17. 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.
Tue 3/248:06 pm
ORD
-
SAN
Nonstop4h 34m
American Airlines
Wed 4/83:12 pm
SAN
-
ORD
Nonstop4h 23m
American Airlines
Deal found 2/17$167
This American Airlines deal was found by Cheapflights users on 2/20. 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.
Fri 4/109:00 pm
ORD
-
SAN
Nonstop4h 33m
American Airlines
Wed 4/151:03 pm
SAN
-
ORD
Nonstop4h 29m
American Airlines
Deal found 2/20$168
This Kiwi.com deal was found by Cheapflights users on 2/18. 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.
Fri 4/241:30 pm
MDW
-
SAN
1 stop26h 54m
Frontier
Wed 4/298:00 am
SAN
-
MDW
2 stops12h 14m
Frontier
Deal found 2/18$169
This Kiwi.com deal was found by Cheapflights users on 2/19. 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 4/43:35 pm
ORD
-
SAN
1 stop17h 46m
Frontier
Wed 4/82:49 pm
SAN
-
ORD
2 stops12h 50m
Frontier
Deal found 2/19$169
This United Airlines deal was found by Cheapflights users on 2/18. 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.
Fri 4/38:20 pm
ORD
-
SAN
Nonstop4h 39m
United Airlines
Wed 4/810:30 pm
SAN
-
ORD
Nonstop4h 05m
United Airlines
Deal found 2/18$170
This Southwest deal was found by Cheapflights users on 2/20. 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 4/256:15 am
MDW
-
SAN
Nonstop4h 15m
Southwest
Mon 4/2710:40 pm
SAN
-
MDW
Nonstop3h 55m
Southwest
Deal found 2/20$171
This Kiwi.com deal was found by Cheapflights users on 2/19. 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 4/258:55 am
ORD
-
SAN
1 stop7h 29m
Frontier
Mon 4/279:00 pm
SAN
-
ORD
1 stop7h 08m
Frontier
Deal found 2/19$171
This Orbitz deal was found by Cheapflights users on 2/18. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/112:07 pm
ORD
-
SAN
1 stop8h 05m
Alaska Airlines
Wed 3/187:55 am
SAN
-
ORD
Nonstop4h 26m
Alaska Airlines
Deal found 2/18$172
This WAYA deal was found by Cheapflights users on 2/17. 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 WAYA is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/117:40 am
ORD
-
SAN
Nonstop4h 49m
Multiple Airlines
Mon 3/169:58 pm
SAN
-
ORD
1 stop6h 10m
Multiple Airlines
Deal found 2/17$173
This Expedia deal was found by Cheapflights users on 2/18. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/154:10 pm
ORD
-
SAN
Nonstop4h 45m
Multiple Airlines
Sat 4/186:35 pm
SAN
-
ORD
1 stop10h 12m
Multiple Airlines
Deal found 2/18$174
This Kiwi.com deal was found by Cheapflights users on 2/18. 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.
Mon 3/98:55 pm
ORD
-
SAN
1 stop18h 18m
Frontier
Mon 3/166:25 am
SAN
-
ORD
1 stop16h 32m
Frontier
Deal found 2/18$175
This Kiwi.com deal was found by Cheapflights users on 2/17. 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.
Fri 5/16:15 am
MDW
-
SAN
1 stop10h 10m
Frontier
Mon 5/46:55 am
SAN
-
MDW
1 stop13h 26m
Frontier
Deal found 2/17$176

Find 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 February 21, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$167
(United Airlines)

One-way from

$59
(Trip.com)

Popular in

May

Cheapest in

October

Average price

$247

Good round-trip deal

$202 or less

Good one-way deal

$78 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. 15% potential increase in price ($52 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($8 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in February 2026
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

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 February 21, 2026.
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

MDW - SAN

MDWSAN

Chicago Midway

Sat 4/25

6:15 am-8:30 am

Nonstop4h 15m

San Diego

Mon 4/27

10:40 pm-4:35 am

Nonstop3h 55m

$171

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Fri 4/3

8:20 pm-10:59 pm

Nonstop4h 39m

San Diego

Wed 4/8

10:30 pm-4:35 am

Nonstop4h 05m

$172

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Thu 5/7

8:45 pm-11:10 pm

Nonstop4h 25m

San Diego

Mon 5/11

10:40 pm-4:35 am

Nonstop3h 55m

$177

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Fri 5/1

12:57 pm-3:33 pm

Nonstop4h 36m

San Diego

Mon 5/4

4:49 pm-10:59 pm

Nonstop4h 10m

$177

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Wed 4/15

12:15 pm-5:35 pm

1 stop7h 20m

San Diego

Sat 4/18

6:20 am-12:20 pm

Nonstop4h 00m

$177

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Thu 3/12

7:05 am-9:47 am

Nonstop4h 42m

San Diego

Sun 3/15

10:30 pm-4:29 am

Nonstop3h 59m

$177

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Fri 4/24

4:15 pm-6:51 pm

Nonstop4h 36m

San Diego

Mon 4/27

7:40 pm-5:27 am

1 stop7h 47m

$183

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Fri 4/3

8:55 pm-11:25 pm

Nonstop4h 30m

San Diego

Wed 4/8

10:40 pm-4:35 am

Nonstop3h 55m

$187

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Tue 3/17

5:55 am-10:30 am

1 stop6h 35m

San Diego

Tue 3/24

10:40 pm-4:35 am

Nonstop3h 55m

$187

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Tue 4/14

8:20 pm-10:59 pm

Nonstop4h 39m

San Diego

Tue 4/21

12:40 pm-9:20 pm

1 stop6h 40m

$187

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/17

Showing 1-10 of 60 results
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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, April is the cheapest month in which you can book a flight from Illinois to San Diego (average of $82). Flying from Illinois to San Diego in December is currently the most expensive (average of $157). 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 February 21, 2026.

A simple way to save on the total cost of your ticket is to fly from Illinois to San Diego in the evening. If you’re flexible enough to do this you can expect to save up to 17% on your trip compared to booking a flight at noon.

What is the cheapest day to fly from Illinois to San Diego?

Use this chart to determine the cheapest time to fly round-trip from Illinois to San Diego. Price data was last updated on February 17, 2026.

Travelers seeking maximum savings on their Illinois to San Diego flight should consider departing on Saturday at noon when fares are most often at their lowest. Monday mornings flights should be avoided if possible as fares are typically the most expensive at this time.

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 February 21, 2026.

The most flights from USIL to SAN are scheduled on a Friday (35 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (21 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 $171, Southwest 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 Spirit Airlines, which is currently one of the cheapest options available, starting at $43. Frontier flights start at $57 while deals on Hawaiian Airlines start at $69 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 Emirates (100%), United Airlines (79%) or Austrian 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 $78. On average you can expect to pay $680. The most popular route, (Chicago O'Hare Intl - San Diego), can usually be booked for $137.

  • 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, April is the cheapest month in which you can book a flight from Illinois to San Diego (average of $82). Flying from Illinois to San Diego in December is currently the most expensive (average of $157). 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
National City
Coronado
La Mesa
Poway
Julian
Lemon Grove

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Alternative routes for Illinois to San Diego

See prices for flight routes from nearby airports that may be better suited for you.
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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 February 21, 2026.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$87Average$184FlexibilityNo cancel feeOn-time65%
FrontierCheapest$98Average$257FlexibilityNo cancel feeOn-time62%
DeltaCheapest$128Average$297FlexibilityNo cancel feeOn-timeN/A
Hawaiian AirlinesCheapest$138Average$255FlexibilityNo cancel feeOn-time85%
Alaska AirlinesCheapest$143Average$262FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$157Average$390FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$158Average$422FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$177Average$353FlexibilityNo cancel feeOn-time63%

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