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$60+ 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 1/17. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SAN
Dec 18 — Dec 251
Thu 12/18
Thu 12/25
1 adult, Economy
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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 November 18, 2025.

This CheapOair deal was found by Cheapflights users on 11/17. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/227:43 pmSTL - SAN
1 stop25h 32mFrontier
Wed 1/147:10 amSAN - STL
1 stop5h 38mFrontier
Deal found 11/17$137
This Expedia deal was found by Cheapflights users on 11/17. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/2010:10 pmSTL - SAN
1 stop16h 01mFrontier
Sun 12/281:06 pmSAN - STL
1 stop6h 19mFrontier
Deal found 11/17$144
This Southwest deal was found by Cheapflights users on 11/16. 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.
Wed 12/241:55 pmMDW - SAN
Nonstop4h 20mSouthwest
Wed 12/313:15 pmSAN - MDW
1 stop5h 40mSouthwest
Deal found 11/16$163
This Kiwi.com deal was found by Cheapflights users on 11/17. 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.
Mon 12/89:27 pmORD - SAN
1 stop22h 26mFrontier
Sat 12/134:47 pmSAN - ORD
1 stop29h 25mFrontier
Deal found 11/17$164
This Alaska Airlines deal was found by Cheapflights users on 11/17. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/118:55 amORD - SAN
Nonstop4h 27mAlaska Airlines
Wed 12/171:45 pmSAN - ORD
Nonstop4h 09mAlaska Airlines
Deal found 11/17$165
This Kiwi.com deal was found by Cheapflights users on 11/15. 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 12/177:43 pmSTL - SAN
1 stop25h 32mFrontier
Thu 12/251:06 pmSAN - STL
2 stops18h 56mFrontier
Deal found 11/15$165
This Expedia deal was found by Cheapflights users on 11/17. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/153:05 pmORD - SAN
Nonstop4h 28mMultiple Airlines
Mon 12/227:21 pmSAN - ORD
1 stop16h 56mMultiple Airlines
Deal found 11/17$166
This Southwest deal was found by Cheapflights users on 11/16. 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.
Sun 12/77:45 amMDW - SAN
Nonstop4h 25mSouthwest
Tue 12/96:30 amSAN - MDW
Nonstop4h 05mSouthwest
Deal found 11/16$167
This United Airlines deal was found by Cheapflights users on 11/17. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/88:50 amORD - SAN
Nonstop4h 40mUnited Airlines
Sat 12/132:16 pmSAN - ORD
Nonstop4h 09mUnited Airlines
Deal found 11/17$167
This Orbitz deal was found by Cheapflights users on 11/17. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/118:59 pmORD - SAN
Nonstop4h 28mMultiple Airlines
Thu 12/186:25 amSAN - ORD
1 stop10h 27mMultiple Airlines
Deal found 11/17$168
This American Airlines deal was found by Cheapflights users on 11/17. 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.
Wed 12/178:15 amORD - SAN
Nonstop4h 33mAmerican Airlines
Sun 1/116:20 amSAN - ORD
Nonstop4h 09mAmerican Airlines
Deal found 11/17$170
This Kiwi.com deal was found by Cheapflights users on 11/15. 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 12/177:43 pmSTL - SAN
1 stop25h 32mFrontier
Wed 12/314:47 pmSAN - STL
2 stops14h 53mFrontier
Deal found 11/15$170

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 November 18, 2025.

Most accurate provider

Mytrip
3 stars

Most trusted provider

Mytrip
3 stars

Round-trip from

$130
(Frontier)

One-way from

$60
(Trip.com)

Popular in

March

Cheapest in

October

Average price

$333

Good round-trip deal

$190 or less

Good one-way deal

$97 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. 17% potential increase in price ($69 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($12 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in November 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

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 November 18, 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

MDW - SAN

MDWSAN

Chicago Midway

Wed 12/24

1:55 pm-4:15 pm

Nonstop4h 20m

San Diego

Wed 12/31

3:15 pm-10:55 pm

1 stop5h 40m

$163

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Thu 1/8

7:50 pm-10:20 pm

Nonstop4h 30m

San Diego

Sun 1/18

6:25 am-12:25 pm

Nonstop4h 00m

$165

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Sun 12/7

7:45 am-10:10 am

Nonstop4h 25m

San Diego

Tue 12/9

6:30 am-12:35 pm

Nonstop4h 05m

$167

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Wed 2/11

6:00 am-10:10 am

1 stop6h 10m

San Diego

Wed 2/18

2:00 pm-9:15 pm

1 stop5h 15m

$174

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Sun 12/7

3:00 pm-5:25 pm

Nonstop4h 25m

San Diego

Fri 12/12

6:35 am-12:40 pm

Nonstop4h 05m

$177

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Thu 1/8

7:50 pm-10:20 pm

Nonstop4h 30m

San Diego

Mon 1/12

6:25 am-12:25 pm

Nonstop4h 00m

$177

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Fri 1/16

8:35 pm-11:05 pm

Nonstop4h 30m

San Diego

Mon 1/19

6:30 pm-12:25 am

Nonstop3h 55m

$177

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Mon 12/8

8:35 pm-11:00 pm

Nonstop4h 25m

San Diego

Thu 12/11

5:00 pm-10:55 pm

Nonstop3h 55m

$177

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Wed 1/7

8:25 am-1:20 pm

1 stop6h 55m

San Diego

Tue 1/13

7:30 am-4:35 pm

2 stops7h 05m

$182

St. LouisSan Diego

STL - SAN

STLSAN

Lambert-St Louis

Tue 12/23

10:10 pm-12:11 pm

1 stop16h 01m

San Diego

Wed 1/14

7:10 am-2:48 pm

1 stop5h 38m

$201

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/18

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, September is the cheapest month in which you can book a flight from Illinois to San Diego (average of $88). Flying from Illinois to San Diego in November is currently the most expensive (average of $153). 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 November 18, 2025.

A simple way to save on the total cost of your ticket is to fly from Illinois to San Diego at noon. If you’re flexible enough to do this you can expect to save up to 8% on your trip compared to booking a flight in the morning.

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 December 16, 2024.

Travelers seeking maximum savings on their Illinois to San Diego flight should consider departing on Tuesday mornings 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 November 18, 2025.

The most flights from USIL to SAN are scheduled on a Tuesday (32 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (7 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 $163, Southwest can have you in San Diego from Illinois in 4h 20m. 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 $65. 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 (83%), United Airlines (79%) or Air Canada (78%) 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 $76. On average you can expect to pay $657. The most popular route, (Chicago O'Hare Intl - San Diego), can usually be booked for $142.

  • 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, September is the cheapest month in which you can book a flight from Illinois to San Diego (average of $88). Flying from Illinois to San Diego in November is currently the most expensive (average of $153). 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
National City

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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 November 18, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$87Average$201FlexibilityNo cancel feeOn-time65%
FrontierCheapest$104Average$206FlexibilityNo cancel feeOn-time62%
Alaska AirlinesCheapest$142Average$230FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$165Average$449FlexibilityNo cancel feeOn-time71%
Hawaiian AirlinesCheapest$168Average$237FlexibilityNo cancel feeOn-time85%
United AirlinesCheapest$172Average$467FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$195Average$457FlexibilityNo cancel feeOn-time63%
DeltaCheapest$223Average$330FlexibilityNo cancel feeOn-timeN/A

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