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$78+ Cheap flights from San Francisco (SFO) 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 11/6. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — ORD
Oct 16 — Oct 231
Thu 10/16
Thu 10/23
1 adult, Economy
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Cheap flight deals from San Francisco to Illinois

Keep the following information in mind while searching for San Francisco to Illinois flight deals. Data was last updated September 16, 2025.

Round-trip from

$206
(Kiwi.com)

One-way from

$78
(Cheapflightsfares)

Popular in

December

Cheapest in

February

Average price

$317

Good round-trip deal

$303 or less

Good one-way deal

$160 or less
From San Francisco to Illinois
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One-way flight from San Francisco to Illinois
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Highest demand for flights based on searches. 9% potential increase in price ($36 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($10 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Price to beat on a round-trip flight from San Francisco to Illinois.
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Price to beat on a one-way flight from San Francisco to Illinois.
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Find flight deals from San Francisco to Illinois

Cheapest flights from San Francisco to Illinois
Explore the most affordable flight options available from San Francisco to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 16, 2025.

This Kiwi.com deal was found by Cheapflights users on 9/16. 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.
Fri 10/319:55 pmSFO - MDW
1 stop15h 02mFrontier
Fri 11/71:37 pmMDW - SFO
1 stop9h 34mFrontier
Deal found 9/16$206
This Kiwi.com deal was found by Cheapflights users on 9/16. 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.
Sat 10/46:00 amSFO - ORD
1 stop10h 14mMultiple Airlines
Tue 10/76:40 amORD - SFO
1 stop16h 42mMultiple Airlines
Deal found 9/16$206
This CheapOair deal was found by Cheapflights users on 9/14. 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 11/136:33 pmSFO - MDW
2 stops14h 57mFrontier
Mon 11/1712:30 pmMDW - SFO
1 stop13h 44mFrontier
Deal found 9/14$207
This Kiwi.com deal was found by Cheapflights users on 9/14. 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 11/1510:23 pmSFO - ORD
1 stop10h 15mMultiple Airlines
Wed 11/192:54 pmORD - SFO
1 stop9h 07mMultiple Airlines
Deal found 9/14$207
This CheapOair deal was found by Cheapflights users on 9/16. 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.
Mon 9/2911:00 pmSFO - MDW
1 stop14h 58mFrontier
Fri 10/35:15 pmMDW - SFO
1 stop30h 06mFrontier
Deal found 9/16$208
This Kiwi.com deal was found by Cheapflights users on 9/13. 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 10/186:44 amSFO - ORD
1 stop15h 09mMultiple Airlines
Tue 10/216:40 amORD - SFO
1 stop16h 42mMultiple Airlines
Deal found 9/13$208
This Kiwi.com deal was found by Cheapflights users on 9/15. 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.
Thu 10/25:45 amSFO - ORD
1 stop13h 51mMultiple Airlines
Mon 10/610:19 pmORD - SFO
1 stop25h 03mMultiple Airlines
Deal found 9/15$209
This Priceline deal was found by Cheapflights users on 9/15. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/2811:57 pmSFO - MDW
1 stop11h 14mFrontier
Mon 10/206:24 pmMDW - SFO
1 stop7h 50mFrontier
Deal found 9/15$210
This CheapOair deal was found by Cheapflights users on 9/14. 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.
Fri 9/2611:57 pmSFO - ORD
1 stop22h 01mFrontier
Tue 9/307:20 amORD - SFO
1 stop17h 10mFrontier
Deal found 9/14$210
This CheapOair deal was found by Cheapflights users on 9/15. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/1310:17 pmSFO - MDW
2 stops23h 03mFrontier
Mon 10/205:10 amMDW - SFO
1 stop12h 50mFrontier
Deal found 9/15$211
This CheapOair deal was found by Cheapflights users on 9/14. 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 11/58:00 amSFO - ORD
2 stops27h 06mFrontier
Sat 11/86:25 pmORD - SFO
1 stop19h 50mFrontier
Deal found 9/14$211
This CheapOair deal was found by Cheapflights users on 9/16. 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.
Thu 10/211:57 pmSFO - MDW
1 stop18h 55mFrontier
Mon 10/206:24 pmMDW - SFO
1 stop7h 50mFrontier
Deal found 9/16$212

Cheapflights Fare Finder

 
Customize your flight search to find flights from San Francisco 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 September 16, 2025.
Use the filters below to find and compare flights from San Francisco to Illinois that are best for you.

Fly from

San Francisco

Fly to

Illinois

Route

Depart

Return

Price

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Tue 11/11

7:00 am-7:55 pm

1 stop10h 55m

Chicago O'Hare Intl

Wed 11/12

2:54 pm-10:01 pm

1 stop9h 07m

$218

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Tue 11/11

7:00 am-7:55 pm

1 stop10h 55m

Chicago O'Hare Intl

Wed 11/19

2:54 pm-10:01 pm

1 stop9h 07m

$218

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Thu 11/13

7:00 am-11:59 pm

1 stop14h 59m

Chicago O'Hare Intl

Wed 11/19

9:20 am-10:01 pm

1 stop14h 41m

$241

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Tue 12/16

7:00 am-11:50 pm

1 stop14h 50m

Chicago O'Hare Intl

Tue 1/6

8:20 am-12:27 am

1 stop18h 07m

$250

San FranciscoSt. Louis

SFO - STL

SFOSTL

San Francisco

Wed 11/5

10:35 am-4:27 pm

Nonstop3h 52m

Lambert-St Louis

Sat 11/8

5:29 pm-8:07 pm

Nonstop4h 38m

$253

San FranciscoSt. Louis

SFO - STL

SFOSTL

San Francisco

Fri 11/28

6:00 am-4:49 pm

1 stop8h 49m

Lambert-St Louis

Wed 12/3

6:00 am-1:34 pm

1 stop9h 34m

$257

San FranciscoSt. Louis

SFO - STL

SFOSTL

San Francisco

Wed 11/26

12:45 am-11:59 am

1 stop9h 14m

Lambert-St Louis

Wed 12/3

6:00 am-1:34 pm

1 stop9h 34m

$257

San FranciscoSt. Louis

SFO - STL

SFOSTL

San Francisco

Thu 11/27

6:00 am-3:05 pm

1 stop7h 05m

Lambert-St Louis

Thu 12/4

6:00 am-12:36 pm

1 stop8h 36m

$257

San FranciscoSt. Louis

SFO - STL

SFOSTL

San Francisco

Tue 11/4

12:35 am-8:51 am

1 stop6h 16m

Lambert-St Louis

Sat 11/8

12:14 pm-5:24 pm

1 stop7h 10m

$257

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Mon 10/20

9:17 pm-2:50 pm

1 stop15h 33m

Chicago O'Hare Intl

Tue 10/28

9:20 am-10:01 pm

1 stop14h 41m

$258

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/14

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

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

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

Currently, August is the cheapest month in which you can book a flight from San Francisco to Illinois (average of $245). Flying from San Francisco 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 SFO to IL?

Find hourly flight availability from San Francisco 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 September 16, 2025.

When flying from San Francisco 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 Francisco to Illinois

Explore weekly flight availability from San Francisco 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 September 16, 2025.

The most flights from SFO to USIL are scheduled on a Monday (94 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (57 on average).

How much does it cost to fly round-trip from San Francisco 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 September 16, 2025.
Get a feel of what it's like to fly with Alaska Airlines, Southwest, and United Airlines from San Francisco to Illinois by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Comfort

7.8

Entertainment

7.1

Overall

8.0

Boarding

8.1

Crew

8.5

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
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Comfort

7.8

Entertainment

7.1

Overall

8.0

Boarding

8.1

Crew

8.5

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
4,242 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Comfort

7.8

Entertainment

7.1

Overall

8.0

Boarding

8.1

Crew

8.5

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
8,924 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Comfort

7.8

Entertainment

7.1

Overall

8.0

Boarding

8.1

Crew

8.5

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
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Comfort

7.8

Entertainment

7.1

Overall

8.0

Boarding

8.1

Crew

8.5

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
3,174 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Comfort

7.8

Entertainment

7.1

Overall

8.0

Boarding

8.1

Crew

8.5

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 Francisco 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 Francisco to Illinois?

    Most people fly from San Francisco (SFO) if they book a flight from San Francisco to Illinois. San Francisco is conveniently located just 11.8 mi from San Francisco’s city center.

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

    For as low as $253, Alaska Airlines can have you in Illinois from San Francisco in 3h 52m. Airlines will cover a distance of 1730 mi. This flight may include one or multiple stops.

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

    To fly one-way, consider booking your trip with United Airlines, which is currently one of the cheapest options available, starting at $82. Frontier flights start at $89 while deals on Southwest start at $92 one-way.

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

    The most popular route from San Francisco to Illinois is San Francisco - Chicago O'Hare Intl. You may also consider San Francisco - Chicago Midway or San Francisco - Lambert-St Louis.

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

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from San Francisco to Illinois on time: ITA Airways (100%), Fiji Airways (83%), Asiana Airlines (83%).

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

    Looking at all options, your cheapest flight can be booked for $104. While the most popular route (San Francisco - Chicago O'Hare Intl) can be booked for $156 on average, our data indicates $881 when flying from San Francisco to Illinois.

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

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

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

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

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

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

    Currently, August is the cheapest month in which you can book a flight from San Francisco to Illinois (average of $245). Flying from San Francisco 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 Francisco 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 Francisco to Illinois

Discover the top 7 airlines that operate flights from San Francisco 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 September 16, 2025.
AirlineCheapestAverageFlexibilityOn-time
Hawaiian AirlinesCheapest$108Average$288FlexibilityNo cancel feeOn-time85%
FrontierCheapest$127Average$232FlexibilityNo cancel feeOn-time62%
DeltaCheapest$128Average$330FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$133Average$444FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$185Average$336FlexibilityNo cancel feeOn-time63%
Alaska AirlinesCheapest$196Average$314FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$197Average$456FlexibilityNo cancel feeOn-time71%

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