HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Illinois

$72+ 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 10/30. Fares are subject to change and may not be available on all flights or dates of travel.
SAN — ORD
Nov 1 — Nov 81
Sat 11/1
Sat 11/8
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from San Diego to Illinois with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

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 October 2, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$143
(Cheapflightsfares)

One-way from

$72
(Frontier)

Popular in

December

Cheapest in

August

Average price

$262

Good round-trip deal

$249 or less

Good one-way deal

$131 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. 13% potential increase in price ($55 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($9 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in October 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

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 October 2, 2025.

This Priceline deal was found by Cheapflights users on 9/30. 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 10/249:03 pmSAN - STL
1 stop10h 04mFrontier
Sat 10/254:51 pmSTL - SAN
1 stop6h 00mFrontier
Deal found 9/30$144
This Cheapflightsfares deal was found by Cheapflights users on 9/30. 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 11/211:43 pmSAN - ORD
Nonstop4h 10mAlaska Airlines
Mon 11/248:20 amORD - SAN
Nonstop4h 26mAlaska Airlines
Deal found 9/30$145
This Booking.com deal was found by Cheapflights users on 9/30. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/15:28 pmSAN - STL
1 stop14h 39mFrontier
Tue 11/47:45 pmSTL - SAN
1 stop18h 07mFrontier
Deal found 9/30$145
This Kiwi.com deal was found by Cheapflights users on 10/2. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/155:49 pmSAN - ORD
Nonstop4h 10mHawaiian Airlines
Mon 11/248:49 pmORD - SAN
Nonstop4h 24mHawaiian Airlines
Deal found 10/2$146
This Booking.com deal was found by Cheapflights users on 9/30. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/216:41 amSAN - STL
1 stop24h 26mFrontier
Fri 10/247:52 pmSTL - SAN
1 stop5h 58mFrontier
Deal found 9/30$146
This Cheapflightsfares deal was found by Cheapflights users on 9/29. 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.
Tue 11/45:49 pmSAN - ORD
Nonstop4h 10mAlaska Airlines
Wed 11/58:59 pmORD - SAN
Nonstop4h 20mAlaska Airlines
Deal found 9/29$149
This Kiwi.com deal was found by Cheapflights users on 9/30. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/156:41 amSAN - ORD
1 stop14h 48mMultiple Airlines
Mon 11/248:49 pmORD - SAN
Nonstop4h 24mMultiple Airlines
Deal found 9/30$151
This Cheapflightsfares deal was found by Cheapflights users on 10/2. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/115:49 pmSAN - ORD
Nonstop4h 10mAlaska Airlines
Wed 11/128:59 pmORD - SAN
Nonstop4h 20mAlaska Airlines
Deal found 10/2$152
This American Airlines deal was found by Cheapflights users on 9/30. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/110:53 amSAN - ORD
Nonstop4h 28mAmerican Airlines
Tue 11/48:20 amORD - SAN
Nonstop4h 30mAmerican Airlines
Deal found 9/30$153
This CheapOair deal was found by Cheapflights users on 9/30. 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.
Thu 10/3010:14 amSAN - ORD
1 stop13h 01mFrontier
Sat 11/17:15 amORD - SAN
1 stop17h 10mFrontier
Deal found 9/30$154
This Frontier deal was found by Cheapflights users on 9/29. 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.
Thu 11/139:14 amSAN - MDW
1 stop6h 08mFrontier
Sun 11/1611:21 amMDW - SAN
1 stop9h 13mFrontier
Deal found 9/29$154
This Frontier deal was found by Cheapflights users on 9/30. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/318:30 amSAN - ORD
1 stop11h 13mFrontier
Sun 11/25:00 amORD - SAN
1 stop7h 17mFrontier
Deal found 9/30$155

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 October 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 10/24

9:03 pm-9:07 am

1 stop10h 04m

Lambert-St Louis

Sat 10/25

4:51 pm-8:51 pm

1 stop6h 00m

$144

San DiegoSt. Louis

SAN - STL

SANSTL

San Diego

Fri 10/31

8:30 am-8:12 pm

1 stop9h 42m

Lambert-St Louis

Sun 11/2

12:20 pm-6:29 pm

1 stop8h 09m

$144

San DiegoSt. Louis

SAN - STL

SANSTL

San Diego

Thu 10/30

6:25 am-5:27 pm

1 stop9h 02m

Lambert-St Louis

Sun 11/2

12:20 pm-6:29 pm

1 stop8h 09m

$144

San DiegoSt. Louis

SAN - STL

SANSTL

San Diego

Fri 10/10

8:11 am-10:14 pm

1 stop12h 03m

Lambert-St Louis

Mon 10/13

9:59 pm-9:20 pm

1 stop25h 21m

$145

San DiegoSt. Louis

SAN - STL

SANSTL

San Diego

Tue 10/21

6:41 am-9:07 am

1 stop24h 26m

Lambert-St Louis

Fri 10/24

7:52 pm-11:50 pm

1 stop5h 58m

$146

San DiegoChicago

SAN - ORD

SANORD

San Diego

Tue 2/17

8:05 am-1:59 pm

Nonstop3h 54m

Chicago O'Hare Intl

Tue 2/24

9:00 am-11:25 am

Nonstop4h 25m

$165

San DiegoChicago

SAN - ORD

SANORD

San Diego

Thu 2/12

5:00 pm-11:10 pm

Nonstop4h 10m

Chicago O'Hare Intl

Wed 2/18

2:59 pm-5:24 pm

Nonstop4h 25m

$175

San DiegoChicago

SAN - ORD

SANORD

San Diego

Mon 11/17

1:41 pm-7:55 pm

Nonstop4h 14m

Chicago O'Hare Intl

Wed 11/19

8:59 pm-11:19 pm

Nonstop4h 20m

$175

San DiegoChicago

SAN - ORD

SANORD

San Diego

Wed 10/29

12:45 pm-6:59 pm

Nonstop4h 14m

Chicago O'Hare Intl

Wed 11/5

8:59 pm-11:19 pm

Nonstop4h 20m

$175

San DiegoChicago

SAN - ORD

SANORD

San Diego

Wed 10/29

12:45 pm-6:59 pm

Nonstop4h 14m

Chicago O'Hare Intl

Tue 11/4

8:59 pm-11:19 pm

Nonstop4h 20m

$175

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/2

Showing 1-10 of 60 results
1
2
3
...
6

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 October 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 October 2, 2025.

The most flights from SAN to USIL are scheduled on a Wednesday (43 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (30 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 October 2, 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
10,994 reviews

Overall

8.0

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.1

Comfort

7.8

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
10,994 reviews
Alaska Airlines
8.0
Very good
10,994 reviews

Overall

8.0

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.1

Comfort

7.8

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
4,248 reviews
Alaska Airlines
8.0
Very good
10,994 reviews

Overall

8.0

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.1

Comfort

7.8

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
8,933 reviews
Alaska Airlines
8.0
Very good
10,994 reviews

Overall

8.0

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.1

Comfort

7.8

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
11,033 reviews
Alaska Airlines
8.0
Very good
10,994 reviews

Overall

8.0

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.1

Comfort

7.8

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
3,155 reviews
Alaska Airlines
8.0
Very good
10,994 reviews

Overall

8.0

Boarding

8.1

Entertainment

7.0

Crew

8.5

Food

7.1

Comfort

7.8

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 54m. Fly via Frontier, Alaska Airlines, or Southwest to get the fastest option. There are 1719 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 $77 on Alaska Airlines. Other airlines that offer cheap prices include United Airlines from $77 and Southwest from $86 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 ITA Airways (100%), Austrian Airlines (88%) and Royal Jordanian (87%).

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

    While on average a flight from San Diego to Illinois is generally $799, our data shows the cheapest flight currently is $79. When looking at the most popular route, (San Diego - Chicago O'Hare Intl), you can expect to pay $150 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

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for San Diego to Illinois

See prices for flight routes from nearby airports that may be better suited for you.
Los Angeles to John F Kennedy Intl flights
San Francisco to John F Kennedy Intl flights
San Francisco to Newark flights
Los Angeles to Seattle flights
Los Angeles to Newark flights
Los Angeles to LaGuardia flights
Los Angeles to Dallas/Fort Worth flights
Los Angeles to O'Hare Intl flights
San Francisco to Las Vegas flights
Los Angeles to Honolulu flights
San Francisco to Los Angeles flights
Los Angeles to Las Vegas flights
San Francisco to Dallas/Fort Worth flights
Los Angeles to San Francisco flights
Santa Ana to Seattle flights
San Francisco to LaGuardia flights
Los Angeles to Boston flights
Santa Ana to San Francisco flights
Ontario to Seattle flights
Ontario to John F Kennedy Intl flights
Los Angeles to Portland flights
Los Angeles to Miami flights
San Francisco to Ontario flights
Burbank to Las Vegas flights
San Francisco to Seattle flights
San Jose to Seattle flights
Los Angeles to Orlando flights
San Jose to Las Vegas flights
Santa Ana to Las Vegas flights
Los Angeles to Reagan-National flights
San Jose to Los Angeles flights
San Francisco to O'Hare Intl flights
Los Angeles to Sky Harbor Intl flights
Ontario to San Francisco flights
Santa Ana to Newark flights
Los Angeles to Fort Lauderdale flights
San Francisco to Honolulu flights
San Francisco to Santa Ana flights
Los Angeles to Atlanta flights
San Francisco to Sky Harbor Intl flights
Ontario to O'Hare Intl flights
Los Angeles to Dulles Intl flights
Los Angeles to Nashville flights
Los Angeles to Denver flights
Burbank to Newark flights
Santa Ana to Dallas/Fort Worth flights
San Diego to Seattle flights
San Diego to John F Kennedy Intl flights
Los Angeles to Kahului flights
San Francisco to Boston flights

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 October 2, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$110Average$194FlexibilityNo cancel feeOn-time65%
FrontierCheapest$118Average$207FlexibilityNo cancel feeOn-time62%
Alaska AirlinesCheapest$139Average$268FlexibilityNo cancel feeOn-time75%
Hawaiian AirlinesCheapest$139Average$197FlexibilityNo cancel feeOn-time85%
American AirlinesCheapest$167Average$476FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$207Average$481FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$223Average$415FlexibilityNo cancel feeOn-time63%
DeltaCheapest$256Average$384FlexibilityNo cancel feeOn-timeN/A

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.