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$43+ 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 9/4. Fares are subject to change and may not be available on all flights or dates of travel.
SAN — ORD
Jul 7 — Jul 141
Mon 7/7
Mon 7/14
1 adult, Economy
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Cheap 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 July 2, 2025.

Round-trip from

$128
(Priceline)

One-way from

$43
(Priceline)

Popular in

December

Cheapest in

August

Average price

$322

Good round-trip deal

$279 or less

Good one-way deal

$169 or less
From San Diego to Illinois
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One-way flight from San Diego to Illinois
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Highest demand for flights based on searches. 11% potential increase in price ($48 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($9 potential savings vs. average RT price).
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Average for round-trip flights in July 2025
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Price to beat on a round-trip flight from San Diego to Illinois.
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Price to beat on a one-way flight from San Diego to Illinois.
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Find 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 July 2, 2025.

This Priceline deal was found by Cheapflights users on 6/30. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/56:25 amSAN - STL
1 stop5h 28mFrontier
Sun 9/77:55 pmSTL - SAN
1 stop5h 58mFrontier
Deal found 6/30$128
This Cheapflightsfares deal was found by Cheapflights users on 6/30. 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.
Fri 8/14:44 pmSAN - ORD
Nonstop4h 23mFrontier
Tue 8/51:39 pmORD - SAN
Nonstop4h 20mFrontier
Deal found 6/30$166
This FlightHub deal was found by Cheapflights users on 6/30. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/307:00 pmSAN - ORD
1 stop9h 03mSpirit Airlines
Wed 8/67:08 amORD - SAN
1 stop12h 47mSpirit Airlines
Deal found 6/30$167
This Expedia deal was found by Cheapflights users on 6/30. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/145:19 pmSAN - ORD
Nonstop4h 40mMultiple Airlines
Sun 10/196:51 amORD - SAN
Nonstop4h 22mMultiple Airlines
Deal found 6/30$170
This CheapOair deal was found by Cheapflights users on 6/30. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/238:00 amSAN - MDW
1 stop7h 03mFrontier
Mon 7/2812:35 pmMDW - SAN
1 stop24h 35mFrontier
Deal found 6/30$170
This Southwest deal was found by Cheapflights users on 7/1. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/510:40 amSAN - MDW
Nonstop4h 00mSouthwest
Tue 8/121:35 pmMDW - SAN
Nonstop4h 10mSouthwest
Deal found 7/1$171
This Alaska Airlines deal was found by Cheapflights users on 7/2. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/215:19 pmSAN - ORD
Nonstop4h 40mAlaska Airlines
Tue 10/288:00 amORD - SAN
1 stop8h 44mAlaska Airlines
Deal found 7/2$194
This Hawaiian Airlines deal was found by Cheapflights users on 7/2. 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 Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/2312:20 pmSAN - ORD
Nonstop4h 39mHawaiian Airlines
Mon 10/277:55 pmORD - SAN
Nonstop4h 20mHawaiian Airlines
Deal found 7/2$197
This Mytrip deal was found by Cheapflights users on 6/30. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/48:16 amSAN - RFD
1 stop8h 36mMultiple Airlines
Sun 9/79:16 pmRFD - SAN
1 stop12h 05mMultiple Airlines
Deal found 6/30$197
This Southwest deal was found by Cheapflights users on 7/1. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/246:30 amSAN - ORD
2 stops8h 15mSouthwest
Sun 9/285:25 pmORD - SAN
1 stop7h 15mSouthwest
Deal found 7/1$212
This Mytrip deal was found by Cheapflights users on 6/30. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/307:00 pmSAN - MLI
1 stop14h 46mMultiple Airlines
Sun 8/312:46 pmMLI - SAN
1 stop12h 20mMultiple Airlines
Deal found 6/30$214
This Mytrip deal was found by Cheapflights users on 7/2. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/179:40 pmSAN - PIA
1 stop12h 15mMultiple Airlines
Mon 7/2112:45 pmPIA - SAN
1 stop7h 10mMultiple Airlines
Deal found 7/2$237

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 July 2, 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 9/5

6:25 am-1:53 pm

1 stop5h 28m

Lambert-St Louis

Sun 9/7

7:55 pm-11:53 pm

1 stop5h 58m

$128

San DiegoChicago

SAN - ORD

SANORD

San Diego

Fri 8/1

4:44 pm-11:07 pm

Nonstop4h 23m

Chicago O'Hare Intl

Tue 8/5

1:39 pm-3:59 pm

Nonstop4h 20m

$166

San DiegoChicago

SAN - ORD

SANORD

San Diego

Wed 7/30

7:00 pm-6:03 am

1 stop9h 03m

Chicago O'Hare Intl

Wed 8/6

7:08 am-5:55 pm

1 stop12h 47m

$167

San DiegoChicago

SAN - ORD

SANORD

San Diego

Tue 10/14

5:19 pm-11:59 pm

Nonstop4h 40m

Chicago O'Hare Intl

Sun 10/19

6:51 am-9:13 am

Nonstop4h 22m

$170

San DiegoChicago

SAN - MDW

SANMDW

San Diego

Wed 7/23

8:00 am-5:03 pm

1 stop7h 03m

Chicago Midway

Mon 7/28

12:35 pm-11:10 am

1 stop24h 35m

$170

San DiegoChicago

SAN - MDW

SANMDW

San Diego

Tue 8/5

10:40 am-4:40 pm

Nonstop4h 00m

Chicago Midway

Tue 8/12

1:35 pm-3:45 pm

Nonstop4h 10m

$171

San DiegoChicago

SAN - ORD

SANORD

San Diego

Tue 10/21

5:19 pm-11:59 pm

Nonstop4h 40m

Chicago O'Hare Intl

Wed 10/29

2:00 pm-8:40 pm

1 stop8h 40m

$194

San DiegoChicago

SAN - ORD

SANORD

San Diego

Thu 10/23

12:20 pm-6:59 pm

Nonstop4h 39m

Chicago O'Hare Intl

Mon 10/27

7:55 pm-10:15 pm

Nonstop4h 20m

$197

San DiegoChicago

SAN - RFD

SANRFD

San Diego

Thu 9/4

8:16 am-6:52 pm

1 stop8h 36m

Chicago Greater Rockford

Sun 9/7

9:16 pm-7:21 am

1 stop12h 05m

$197

San DiegoChicago

SAN - ORD

SANORD

San Diego

Wed 9/24

6:30 am-4:45 pm

2 stops8h 15m

Chicago O'Hare Intl

Sun 9/28

5:25 pm-10:40 pm

1 stop7h 15m

$212

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/30

Showing 1-10 of 51 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, August is the cheapest month in which you can book a flight from San Diego to Illinois (average of $245). Flying from San Diego to Illinois in March is currently the most expensive (average of $321). 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 July 2, 2025.

When flying from San Diego to Illinois, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

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 July 2, 2025.

The most flights from SAN to USIL are scheduled on a Tuesday (51 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (3 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 July 2, 2025.
Read reviews from past customers who have flown Alaska Airlines, Southwest, and Delta 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
10,000 reviews

Crew

8.5

Comfort

7.8

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Crew

8.5

Comfort

7.8

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Southwest
8.0
Very good
4,272 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Crew

8.5

Comfort

7.8

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Delta
8.0
Very good
7,983 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Crew

8.5

Comfort

7.8

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Hawaiian Airlines
7.8
Good
2,540 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Crew

8.5

Comfort

7.8

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
United Airlines
7.4
Good
8,861 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Crew

8.5

Comfort

7.8

Entertainment

7.1

Overall

8.0

Boarding

8.1

Food

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

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.

  • 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 $43 on Frontier. Other airlines that offer cheap prices include Spirit Airlines from $87 and Southwest from $96 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 (92%), Royal Jordanian (91%) and Qatar Airways (89%).

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

    While on average a flight from San Diego to Illinois is generally $1,280, our data shows the cheapest flight currently is $107. When looking at the most popular route, (San Diego - Chicago O'Hare Intl), you can expect to pay $126 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, August is the cheapest month in which you can book a flight from San Diego to Illinois (average of $245). Flying from San Diego to Illinois in March is currently the most expensive (average of $321). 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 7 airlines flying from San Diego to Illinois

Discover the top 7 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 July 2, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$92Average$180FlexibilityNo cancel feeOn-time65%
FrontierCheapest$112Average$203FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$217Average$466FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$245Average$497FlexibilityNo cancel feeOn-time69%
DeltaCheapest$258Average$349FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$277Average$686FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$284Average$448FlexibilityNo cancel feeOn-time63%

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