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$57+ Cheap flights from San Diego (SAN) to Illinois

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 1/13. Fares are subject to change and may not be available on all flights or dates of travel.
SAN — ORD
Jan 9 — Jan 161
Fri 1/9
Fri 1/16
1 adult, Economy
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Cheap flight deals from San Diego to Illinois

Cheapest flights from San Diego to Illinois
Explore the most affordable flight options available from San Diego to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 10, 2025.

This Kiwi.com deal was found by Cheapflights users on 12/8. 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 12/316:25 amSAN - ORD
1 stop15h 47mFrontier
Mon 2/29:00 amORD - SAN
1 stop10h 03mFrontier
Deal found 12/8$163
This American Airlines deal was found by Cheapflights users on 12/8. 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 12/313:03 pmSAN - ORD
Nonstop4h 27mAmerican Airlines
Mon 1/511:43 amORD - SAN
Nonstop4h 30mAmerican Airlines
Deal found 12/8$181
This Frontier deal was found by Cheapflights users on 12/8. 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.
Tue 12/306:25 amSAN - ORD
1 stop13h 02mFrontier
Mon 1/57:25 amORD - SAN
1 stop13h 01mFrontier
Deal found 12/8$182
This CheapOair deal was found by Cheapflights users on 12/9. 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.
Wed 12/241:06 pmSAN - ORD
1 stop23h 11mFrontier
Mon 1/57:25 amORD - SAN
1 stop13h 01mFrontier
Deal found 12/9$183
This CheapOair deal was found by Cheapflights users on 12/9. 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.
Tue 12/166:34 amSAN - STL
1 stop25h 40mFrontier
Tue 12/2310:10 pmSTL - SAN
1 stop16h 01mFrontier
Deal found 12/9$183
This CheapOair deal was found by Cheapflights users on 12/8. 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.
Wed 12/316:25 amSAN - ORD
1 stop15h 47mFrontier
Mon 1/57:25 amORD - SAN
1 stop13h 01mFrontier
Deal found 12/8$184
This Kiwi.com deal was found by Cheapflights users on 12/10. 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 12/241:30 pmSAN - ORD
Nonstop4h 32mAlaska Airlines
Tue 1/63:37 pmORD - SAN
Nonstop4h 42mAlaska Airlines
Deal found 12/10$186
This Alaska Airlines deal was found by Cheapflights users on 12/8. 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.
Wed 12/311:30 pmSAN - ORD
Nonstop4h 32mAlaska Airlines
Mon 1/53:37 pmORD - SAN
Nonstop4h 42mAlaska Airlines
Deal found 12/8$187
This Expedia deal was found by Cheapflights users on 12/8. 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.
Tue 12/306:25 amSAN - ORD
1 stop13h 02mMultiple Airlines
Mon 1/53:37 pmORD - SAN
Nonstop4h 42mMultiple Airlines
Deal found 12/8$190
This Super.com deal was found by Cheapflights users on 12/7. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/241:06 pmSAN - ORD
1 stop23h 11mFrontier
Wed 12/317:00 amORD - SAN
1 stop18h 59mFrontier
Deal found 12/7$194
This Expedia deal was found by Cheapflights users on 12/8. 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 12/311:30 pmSAN - ORD
Nonstop4h 32mMultiple Airlines
Mon 1/52:57 pmORD - SAN
1 stop10h 10mMultiple Airlines
Deal found 12/8$195
This Kiwi.com deal was found by Cheapflights users on 12/10. 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 12/241:30 pmSAN - ORD
Nonstop4h 32mAlaska Airlines
Mon 1/58:39 amORD - SAN
Nonstop4h 48mAlaska Airlines
Deal found 12/10$196

Find flight deals from San Diego to Illinois

Keep the following information in mind while searching for San Diego to Illinois flight deals. Data was last updated December 10, 2025.

Most accurate provider

CheapOair
3 stars

Most trusted provider

CheapOair
3 stars

Round-trip from

$130
(Kiwi.com)

One-way from

$57
(Kiwi.com)

Popular in

April

Cheapest in

October

Average price

$287

Good round-trip deal

$276 or less

Good one-way deal

$137 or less
Provider with most accurate pricing for San Diego-Chicago (CHI) flight deals.
Search Deals
Provider most trusted by Cheapflights users for San Diego-Chicago (CHI) flights.
Search Deals
From San Diego to Illinois
Search Deals
One-way flight from San Diego to Illinois
Search Deals
Highest demand for flights based on searches. 19% potential increase in price ($76 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 December 2025
Search Deals
Price to beat on a round-trip flight from San Diego to Illinois.
Search Deals
Price to beat on a one-way flight from San Diego to Illinois.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from San Diego to Illinois 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 December 10, 2025.
Use the filters below to find and compare flights from San Diego to Illinois that are best for you.

Fly from

San Diego

Fly to

Illinois

Route

Depart

Return

Price

San DiegoSt. Louis

SAN - STL

SANSTL

San Diego

Fri 1/23

8:16 pm-2:46 pm

1 stop16h 30m

Lambert-St Louis

Sun 1/25

9:27 pm-8:51 am

1 stop13h 24m

$136

San DiegoChicago

SAN - ORD

SANORD

San Diego

Tue 3/3

5:42 pm-11:59 pm

Nonstop4h 17m

Chicago O'Hare Intl

Tue 3/10

3:07 pm-5:52 pm

Nonstop4h 45m

$157

San DiegoChicago

SAN - MDW

SANMDW

San Diego

Sat 1/10

7:25 am-1:20 pm

Nonstop3h 55m

Chicago Midway

Sat 1/17

7:40 pm-10:10 pm

Nonstop4h 30m

$157

San DiegoChicago

SAN - ORD

SANORD

San Diego

Sat 2/14

5:42 pm-11:59 pm

Nonstop4h 17m

Chicago O'Hare Intl

Tue 2/17

3:07 pm-5:52 pm

Nonstop4h 45m

$157

San DiegoChicago

SAN - MDW

SANMDW

San Diego

Sat 1/17

7:25 am-1:20 pm

Nonstop3h 55m

Chicago Midway

Sat 1/24

8:25 am-11:05 am

Nonstop4h 40m

$157

San DiegoChicago

SAN - MDW

SANMDW

San Diego

Sat 1/10

7:25 am-1:20 pm

Nonstop3h 55m

Chicago Midway

Wed 1/21

7:50 pm-10:20 pm

Nonstop4h 30m

$157

San DiegoChicago

SAN - ORD

SANORD

San Diego

Tue 3/10

11:08 am-5:10 pm

Nonstop4h 02m

Chicago O'Hare Intl

Thu 3/12

1:01 pm-3:39 pm

Nonstop4h 38m

$167

San DiegoChicago

SAN - ORD

SANORD

San Diego

Wed 2/4

5:10 pm-11:37 pm

Nonstop4h 27m

Chicago O'Hare Intl

Mon 2/9

3:44 pm-6:26 pm

Nonstop4h 42m

$167

San DiegoChicago

SAN - ORD

SANORD

San Diego

Sat 2/28

5:42 pm-11:59 pm

Nonstop4h 17m

Chicago O'Hare Intl

Sun 3/8

8:20 am-11:09 am

Nonstop4h 49m

$167

San DiegoChicago

SAN - MDW

SANMDW

San Diego

Wed 2/4

6:25 am-12:25 pm

Nonstop4h 00m

Chicago Midway

Mon 2/9

8:35 pm-11:05 pm

Nonstop4h 30m

$167

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/10

Showing 1-10 of 60 results
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Best time to book a flight from San Diego to Illinois

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

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

Currently, February is the cheapest month in which you can book a flight from San Diego to Illinois (average of $88). Flying from San Diego to Illinois in May is currently the most expensive (average of $175). 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 SAN to IL?

Find hourly flight availability from San Diego to Illinois. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated December 10, 2025.

When flying from San Diego to Illinois, the time of day you fly usually plays a role in the price. Save by searching for a flight in the afternoon, which can drop the price by up to 36% versus a flight in the evening.

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

Use this chart to determine the cheapest time to fly round-trip from San Diego to Illinois. Price data was last updated on December 16, 2024.

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

Weekly flight availability from San Diego to Illinois

Explore weekly flight availability from San Diego to Illinois. 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 December 10, 2025.

The most flights from SAN to USIL are scheduled on a Wednesday (37 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (26 on average).

Reviews of airlines servicing Illinois

Get insights into the airlines that provide service to Illinois. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Illinois. Reviews last updated December 10, 2025.
Read reviews from past customers who have flown Alaska Airlines, Southwest, and United Airlines from San Diego to Illinois. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
11,426 reviews

Entertainment

7.0

Boarding

8.1

Comfort

7.8

Food

7.1

Crew

8.5

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Art,Dec 2025

SAN - OGG

It was a five hour flight and my seat did not recline. I have had three back surgeries and I’m solid bone for my L3 vertebrae all the way to my tailbone. My body has never hurt so much. There was no TV on this flight and only a small can of soda was free.
Alaska Airlines
8.0
Very good
11,426 reviews
Alaska Airlines
8.0
Very good
11,426 reviews

Entertainment

7.0

Boarding

8.1

Comfort

7.8

Food

7.1

Crew

8.5

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Art,Dec 2025

SAN - OGG

It was a five hour flight and my seat did not recline. I have had three back surgeries and I’m solid bone for my L3 vertebrae all the way to my tailbone. My body has never hurt so much. There was no TV on this flight and only a small can of soda was free.
Southwest
7.9
Good
4,252 reviews
Alaska Airlines
8.0
Very good
11,426 reviews

Entertainment

7.0

Boarding

8.1

Comfort

7.8

Food

7.1

Crew

8.5

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Art,Dec 2025

SAN - OGG

It was a five hour flight and my seat did not recline. I have had three back surgeries and I’m solid bone for my L3 vertebrae all the way to my tailbone. My body has never hurt so much. There was no TV on this flight and only a small can of soda was free.
United Airlines
7.4
Good
9,093 reviews
Alaska Airlines
8.0
Very good
11,426 reviews

Entertainment

7.0

Boarding

8.1

Comfort

7.8

Food

7.1

Crew

8.5

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Art,Dec 2025

SAN - OGG

It was a five hour flight and my seat did not recline. I have had three back surgeries and I’m solid bone for my L3 vertebrae all the way to my tailbone. My body has never hurt so much. There was no TV on this flight and only a small can of soda was free.
American Airlines
7.2
Good
11,048 reviews
Alaska Airlines
8.0
Very good
11,426 reviews

Entertainment

7.0

Boarding

8.1

Comfort

7.8

Food

7.1

Crew

8.5

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Art,Dec 2025

SAN - OGG

It was a five hour flight and my seat did not recline. I have had three back surgeries and I’m solid bone for my L3 vertebrae all the way to my tailbone. My body has never hurt so much. There was no TV on this flight and only a small can of soda was free.
Frontier
5.8
Fair
3,085 reviews
Alaska Airlines
8.0
Very good
11,426 reviews

Entertainment

7.0

Boarding

8.1

Comfort

7.8

Food

7.1

Crew

8.5

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Art,Dec 2025

SAN - OGG

It was a five hour flight and my seat did not recline. I have had three back surgeries and I’m solid bone for my L3 vertebrae all the way to my tailbone. My body has never hurt so much. There was no TV on this flight and only a small can of soda was free.

Related info for your journey

Find useful and relevant information for your journey from San Diego to Illinois. 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 from for flights from San Diego to Illinois?

    Located just 2.6 mi from the city center, San Diego (SAN) is the airport most travelers will use when flying to Illinois from San Diego.

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

    There are many flights that can get you from San Diego to Illinois in 3h 55m. Fly via Frontier, Alaska Airlines, or Southwest to get the fastest option. There are 1725 mi between San Diego and Illinois. This flight may include one or multiple stops.

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

    One-way options have recently been found by users for as low as $45 on Spirit Airlines. Other airlines that offer cheap prices include Frontier from $61 and Southwest from $62 one-way.

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

    While some choose either San Diego - Chicago Midway or San Diego - Lambert-St Louis, San Diego - Chicago O'Hare Intl is the most popular route from San Diego to Illinois.

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

    The top 3 most reliable airlines when flying from San Diego to Illinois are Cathay Pacific (93%), Austrian Airlines (89%) and Aer Lingus (86%).

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

    While on average a flight from San Diego to Illinois is generally $834, our data shows the cheapest flight currently is $85. When looking at the most popular route, (San Diego - Chicago O'Hare Intl), you can expect to pay $141 for that flight.

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

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

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

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

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

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

    Currently, February is the cheapest month in which you can book a flight from San Diego to Illinois (average of $88). Flying from San Diego to Illinois in May is currently the most expensive (average of $175). 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

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Alternative routes for San Diego to Illinois

See prices for flight routes from nearby airports that may be better suited for you.
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Top 8 airlines flying from San Diego to Illinois

Discover the top 8 airlines that operate flights from San Diego to Illinois. 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 December 10, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$99Average$181FlexibilityNo cancel feeOn-time65%
FrontierCheapest$110Average$214FlexibilityNo cancel feeOn-time62%
Hawaiian AirlinesCheapest$139Average$197FlexibilityNo cancel feeOn-time85%
Alaska AirlinesCheapest$140Average$262FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$166Average$450FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$191Average$432FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$205Average$390FlexibilityNo cancel feeOn-time63%
DeltaCheapest$256Average$368FlexibilityNo cancel feeOn-timeN/A

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