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$52+ 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 2/7. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SAN
Feb 7 — Feb 141
Sat 2/7
Sat 2/14
1 adult, Economy
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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 January 8, 2026.

Most accurate provider

Mytrip
3 stars

Most trusted provider

Mytrip
3 stars

Round-trip from

$109
(WAYA)

One-way from

$52
(Trip.com)

Popular in

March

Cheapest in

October

Average price

$229

Good round-trip deal

$196 or less

Good one-way deal

$126 or less
Provider with most accurate pricing for Chicago (CHI)-San Diego flight deals.
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Provider most trusted by Cheapflights users for Chicago (CHI)-San Diego flights.
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From Illinois to San Diego
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One-way flight from Illinois to San Diego
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Highest demand for flights based on searches. 13% potential increase in price ($44 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($10 potential savings vs. average RT price).
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Average for round-trip flights in January 2026
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Price to beat on a round-trip flight from Illinois to San Diego.
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Price to beat on a one-way flight from Illinois to San Diego.
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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 January 8, 2026.

This Kiwi.com deal was found by Cheapflights users on 1/6. 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 1/313:46 pmSTL - SAN
1 stop9h 45mFrontier
Fri 2/68:16 pmSAN - STL
1 stop16h 30mFrontier
Deal found 1/6$109
This Kiwi.com deal was found by Cheapflights users on 1/7. 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 2/21:40 pmSTL - SAN
1 stop12h 28mFrontier
Fri 2/68:16 pmSAN - STL
1 stop16h 30mFrontier
Deal found 1/7$110
This Trip.com deal was found by Cheapflights users on 1/6. 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.
Mon 1/261:40 pmSTL - SAN
1 stop12h 28mFrontier
Fri 1/306:30 amSAN - STL
1 stop10h 14mFrontier
Deal found 1/6$114
This Kiwi.com deal was found by Cheapflights users on 1/5. 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.
Wed 2/254:51 pmSTL - SAN
1 stop6h 50mFrontier
Sun 3/19:09 amSAN - STL
1 stop26h 00mFrontier
Deal found 1/5$115
This WAYA deal was found by Cheapflights users on 1/7. 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 1/213:46 pmSTL - SAN
1 stop9h 45mFrontier
Wed 1/287:00 amSAN - STL
1 stop5h 46mFrontier
Deal found 1/7$120
This Kiwi.com deal was found by Cheapflights users on 1/6. 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 1/243:46 pmSTL - SAN
1 stop9h 45mFrontier
Sun 1/258:16 pmSAN - STL
1 stop14h 34mFrontier
Deal found 1/6$131
This Kiwi.com deal was found by Cheapflights users on 1/6. 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 2/73:46 pmSTL - SAN
1 stop9h 45mFrontier
Thu 2/126:25 amSAN - STL
1 stop28h 44mFrontier
Deal found 1/6$135
This Kiwi.com deal was found by Cheapflights users on 1/7. 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 3/21:54 pmSTL - SAN
1 stop12h 14mFrontier
Mon 3/99:58 pmSAN - STL
1 stop19h 13mFrontier
Deal found 1/7$137
This Kiwi.com deal was found by Cheapflights users on 1/7. 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 2/21:40 pmSTL - SAN
1 stop12h 28mFrontier
Wed 2/47:00 amSAN - STL
2 stops36h 06mFrontier
Deal found 1/7$145
This Frontier deal was found by Cheapflights users on 1/7. 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.
Wed 2/184:51 pmSTL - SAN
1 stop6h 50mFrontier
Sat 2/286:25 amSAN - STL
1 stop5h 31mFrontier
Deal found 1/7$146
This Kiwi.com deal was found by Cheapflights users on 1/6. 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 2/212:51 pmSTL - SAN
1 stop11h 17mFrontier
Wed 2/257:11 amSAN - STL
1 stop6h 42mFrontier
Deal found 1/6$147
This Kiwi.com deal was found by Cheapflights users on 1/6. 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.
Thu 2/58:00 amORD - SAN
2 stops18h 08mFrontier
Thu 2/126:25 amSAN - ORD
1 stop14h 49mFrontier
Deal found 1/6$158

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 January 8, 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

Wed 2/4

8:15 am-10:50 am

Nonstop4h 35m

San Diego

Wed 2/11

6:25 am-12:25 pm

Nonstop4h 00m

$164

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Fri 2/20

8:20 am-11:09 am

Nonstop4h 49m

San Diego

Mon 2/23

5:42 pm-11:59 pm

Nonstop4h 17m

$167

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Fri 2/20

7:05 am-9:47 am

Nonstop4h 42m

San Diego

Mon 2/23

5:00 pm-10:59 pm

Nonstop3h 59m

$167

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Sat 3/7

8:55 pm-11:25 pm

Nonstop4h 30m

San Diego

Fri 3/13

10:40 pm-4:35 am

Nonstop3h 55m

$167

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Fri 2/6

9:00 am-11:43 am

Nonstop4h 43m

San Diego

Thu 2/12

5:42 pm-11:59 pm

Nonstop4h 17m

$167

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Sat 2/7

1:00 pm-3:36 pm

Nonstop4h 36m

San Diego

Sun 2/8

4:47 pm-10:59 pm

Nonstop4h 12m

$167

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Mon 3/9

6:05 am-8:35 am

Nonstop4h 30m

San Diego

Thu 3/12

8:40 pm-5:55 am

1 stop7h 15m

$167

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Sun 2/22

8:20 am-11:09 am

Nonstop4h 49m

San Diego

Mon 2/23

5:42 pm-11:59 pm

Nonstop4h 17m

$167

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Tue 2/3

9:00 am-11:43 am

Nonstop4h 43m

San Diego

Fri 2/6

5:10 pm-11:37 pm

Nonstop4h 27m

$167

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Mon 2/23

3:07 pm-5:52 pm

Nonstop4h 45m

San Diego

Fri 2/27

8:35 am-2:58 pm

Nonstop4h 23m

$167

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/5

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 January 8, 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 8% 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 January 3, 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. Sunday evenings 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 January 8, 2026.

The most flights from USIL to SAN are scheduled on a Thursday (24 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (14 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 $164, Southwest can have you in San Diego from Illinois in 4h 35m. Illinois and San Diego are separated by a distance of 1725 mi. Generally, flights for this route are nonstop.

  • 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 Air Canada (79%), United Airlines (75%) or Brussels Airlines (70%) 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 $526. The most popular route, (Chicago O'Hare Intl - San Diego), can usually be booked for $129.

  • 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 January 8, 2026.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$84Average$192FlexibilityNo cancel feeOn-time65%
FrontierCheapest$103Average$224FlexibilityNo cancel feeOn-time62%
Alaska AirlinesCheapest$142Average$255FlexibilityNo cancel feeOn-time75%
Hawaiian AirlinesCheapest$153Average$247FlexibilityNo cancel feeOn-time85%
United AirlinesCheapest$160Average$408FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$161Average$444FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$172Average$387FlexibilityNo cancel feeOn-time63%
DeltaCheapest$256Average$299FlexibilityNo cancel feeOn-timeN/A

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