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$60+ 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 12/16. Fares are subject to change and may not be available on all flights or dates of travel.
SAN — ORD
dic. 18 — dic. 251
jue. 12/18
jue. 12/25
1 adult, Economy
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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 noviembre 18, 2025.

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.
jue. 12/118:10 pmSAN - STL
1 stop12h 04mFrontier
lun. 12/157:43 pmSTL - SAN
1 stop6h 16mFrontier
Deal found 11/17$130
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.
mar. 12/166:34 amSAN - STL
1 stop25h 40mFrontier
jue. 12/185:19 pmSTL - SAN
1 stop21h 19mFrontier
Deal found 11/17$134
This CheapOair 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 12/26:25 amSAN - STL
1 stop25h 49mFrontier
sáb. 12/67:43 pmSTL - SAN
1 stop6h 16mFrontier
Deal found 11/16$137
This American Airlines 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 12/136:15 amSAN - ORD
Nonstop4h 16mAmerican Airlines
mar. 12/169:53 amORD - SAN
Nonstop4h 37mAmerican Airlines
Deal found 11/16$155
This Cheapflightsfares 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 12/101:45 pmSAN - ORD
Nonstop4h 09mAlaska Airlines
sáb. 12/133:05 pmORD - SAN
Nonstop4h 28mAlaska Airlines
Deal found 11/16$156
This Southwest deal was found by Cheapflights users on 11/18. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 12/95:00 pmSAN - MDW
Nonstop3h 55mSouthwest
mié. 12/101:55 pmMDW - SAN
Nonstop4h 20mSouthwest
Deal found 11/18$157
This eDestinos deal was found by Cheapflights users on 11/18. 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 eDestinos is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 12/87:10 amSAN - ORD
1 stop11h 07mMultiple Airlines
vie. 12/1210:05 pmORD - SAN
1 stop24h 02mMultiple Airlines
Deal found 11/18$158
This Expedia 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 12/46:34 amSAN - ORD
1 stop15h 38mMultiple Airlines
dom. 12/73:05 pmORD - SAN
Nonstop4h 28mMultiple Airlines
Deal found 11/16$159
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 12/43:47 pmSAN - ORD
1 stop17h 55mFrontier
dom. 12/79:52 pmORD - SAN
1 stop18h 18mFrontier
Deal found 11/16$164
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.
dom. 12/147:00 amSAN - ORD
Nonstop4h 11mUnited Airlines
mié. 12/177:55 pmORD - SAN
Nonstop4h 35mUnited Airlines
Deal found 11/17$165
This Cheapflightsfares 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 12/78:00 amSAN - ORD
Nonstop4h 09mAlaska Airlines
mar. 12/98:55 amORD - SAN
Nonstop4h 27mAlaska Airlines
Deal found 11/16$166
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.
sáb. 12/135:53 pmSAN - ORD
Nonstop3h 57mAlaska Airlines
lun. 12/153:05 pmORD - SAN
Nonstop4h 28mAlaska Airlines
Deal found 11/17$167

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 noviembre 18, 2025.

Most accurate provider

CheapOair
3 stars

Most trusted provider

CheapOair
3 stars

Round-trip from

$130
(Expedia)

One-way from

$60
(Trip.com)

Popular in

April

Cheapest in

October

Average price

$302

Good round-trip deal

$260 or less

Good one-way deal

$135 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. 18% potential increase in price ($73 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 November 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 noviembre 18, 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

mar. 12/16

6:34 am-10:14 am

1 stop25h 40m

Lambert-St Louis

vie. 12/19

10:10 pm-12:38 pm

1 stop16h 28m

$137

San DiegoChicago

SAN - ORD

SANORD

San Diego

mar. 2/17

5:42 pm-11:59 pm

Nonstop4h 17m

Chicago O'Hare Intl

mar. 2/24

3:07 pm-5:52 pm

Nonstop4h 45m

$155

San DiegoChicago

SAN - MDW

SANMDW

San Diego

vie. 2/13

6:45 pm-12:35 am

Nonstop3h 50m

Chicago Midway

dom. 2/15

8:35 pm-11:05 pm

Nonstop4h 30m

$165

San DiegoChicago

SAN - ORD

SANORD

San Diego

jue. 2/12

5:42 pm-11:59 pm

Nonstop4h 17m

Chicago O'Hare Intl

jue. 2/19

3:07 pm-5:52 pm

Nonstop4h 45m

$165

San DiegoChicago

SAN - MDW

SANMDW

San Diego

sáb. 12/13

7:00 am-1:00 pm

Nonstop4h 00m

Chicago Midway

lun. 12/15

8:35 pm-11:00 pm

Nonstop4h 25m

$167

San DiegoChicago

SAN - ORD

SANORD

San Diego

mar. 12/9

5:53 pm-11:50 pm

Nonstop3h 57m

Chicago O'Hare Intl

jue. 12/11

3:05 pm-5:33 pm

Nonstop4h 28m

$167

San DiegoChicago

SAN - ORD

SANORD

San Diego

mié. 1/28

5:10 pm-11:37 pm

Nonstop4h 27m

Chicago O'Hare Intl

vie. 1/30

9:00 am-11:43 am

Nonstop4h 43m

$167

San DiegoChicago

SAN - ORD

SANORD

San Diego

mié. 1/14

5:10 pm-11:37 pm

Nonstop4h 27m

Chicago O'Hare Intl

lun. 1/19

3:44 pm-6:26 pm

Nonstop4h 42m

$167

San DiegoChicago

SAN - ORD

SANORD

San Diego

sáb. 12/13

5:53 pm-11:50 pm

Nonstop3h 57m

Chicago O'Hare Intl

lun. 12/15

3:05 pm-5:33 pm

Nonstop4h 28m

$167

San DiegoSt. Louis

SAN - STL

SANSTL

San Diego

vie. 1/16

6:25 am-6:32 pm

1 stop10h 07m

Lambert-St Louis

lun. 1/19

8:32 pm-11:31 pm

2 stops28h 59m

$175

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/16

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 $94). Flying from San Diego to Illinois in May is currently the most expensive (average of $173). 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 noviembre 18, 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 38% 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 Sunday mornings when fares are most often at their lowest. Sunday afternoons 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 noviembre 18, 2025.

The most flights from SAN to USIL are scheduled on a Tuesday (37 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (9 on average).

How much does it cost to fly round-trip from San Diego to Illinois?

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 noviembre 18, 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
11,316 reviews

Comfort

7.8

Overall

8.0

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.1

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
Alaska Airlines
8.0
Very good
11,316 reviews
Alaska Airlines
8.0
Very good
11,316 reviews

Comfort

7.8

Overall

8.0

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.1

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
Southwest
8.0
Very good
4,245 reviews
Alaska Airlines
8.0
Very good
11,316 reviews

Comfort

7.8

Overall

8.0

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.1

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
United Airlines
7.4
Good
9,015 reviews
Alaska Airlines
8.0
Very good
11,316 reviews

Comfort

7.8

Overall

8.0

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.1

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
American Airlines
7.2
Good
11,047 reviews
Alaska Airlines
8.0
Very good
11,316 reviews

Comfort

7.8

Overall

8.0

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.1

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
Frontier
5.8
Fair
3,103 reviews
Alaska Airlines
8.0
Very good
11,316 reviews

Comfort

7.8

Overall

8.0

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.1

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.

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 50m. 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 $65 on Frontier. Other airlines that offer cheap prices include Southwest from $86 and Alaska Airlines from $88 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 (90%), Royal Jordanian (88%) and Aer Lingus (85%).

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

    While on average a flight from San Diego to Illinois is generally $893, our data shows the cheapest flight currently is $87. When looking at the most popular route, (San Diego - Chicago O'Hare Intl), you can expect to pay $130 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 $94). Flying from San Diego to Illinois in May is currently the most expensive (average of $173). 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

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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 noviembre 18, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$110Average$206FlexibilityNo cancel feeOn-time65%
FrontierCheapest$119Average$212FlexibilityNo cancel feeOn-time62%
Hawaiian AirlinesCheapest$139Average$197FlexibilityNo cancel feeOn-time85%
Alaska AirlinesCheapest$139Average$262FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$168Average$448FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$200Average$450FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$213Average$401FlexibilityNo cancel feeOn-time63%
DeltaCheapest$256Average$368FlexibilityNo cancel feeOn-timeN/A

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