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$80+ 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 9/20. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — ORD
Aug 19 — Aug 261
Tue 8/19
Tue 8/26
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 August 14, 2025.

Round-trip from

$203
(Frontier)

One-way from

$80
(Priceline)

Popular in

December

Cheapest in

February

Average price

$366

Good round-trip deal

$253 or less

Good one-way deal

$162 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. 6% potential increase in price ($25 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 August 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 August 14, 2025.

This Frontier deal was found by Cheapflights users on 8/13. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/410:19 amSFO - MDW
1 stop9h 39mFrontier
Sat 9/611:23 amMDW - SFO
2 stops11h 58mFrontier
Deal found 8/13$203
This Frontier deal was found by Cheapflights users on 8/14. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/138:00 amSFO - ORD
2 stops13h 58mFrontier
Sat 9/2012:22 pmORD - SFO
1 stop10h 59mFrontier
Deal found 8/14$203
This CheapOair deal was found by Cheapflights users on 8/14. 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 9/1911:57 pmSFO - MDW
1 stop8h 31mFrontier
Mon 9/226:20 amMDW - SFO
1 stop17h 01mFrontier
Deal found 8/14$204
This Alaska Airlines deal was found by Cheapflights users on 8/12. 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 10/2210:26 amSFO - ORD
1 stop11h 33mAlaska Airlines
Sat 11/82:54 pmORD - SFO
1 stop9h 01mAlaska Airlines
Deal found 8/12$204
This Frontier deal was found by Cheapflights users on 8/14. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/185:45 amSFO - MDW
2 stops14h 13mFrontier
Fri 9/193:48 pmMDW - SFO
1 stop10h 28mFrontier
Deal found 8/14$205
This Expedia deal was found by Cheapflights users on 8/14. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/199:31 amSFO - ORD
2 stops12h 28mFrontier
Mon 9/296:00 amORD - SFO
1 stop9h 17mFrontier
Deal found 8/14$205
This FlightHub deal was found by Cheapflights users on 8/14. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/410:45 amSFO - MDW
1 stop27h 08mFrontier
Sun 9/76:20 amMDW - SFO
1 stop17h 01mFrontier
Deal found 8/14$206
This Frontier deal was found by Cheapflights users on 8/14. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/118:00 amSFO - ORD
2 stops13h 59mFrontier
Sun 10/196:50 amORD - SFO
1 stop9h 32mFrontier
Deal found 8/14$206
This Southwest deal was found by Cheapflights users on 8/13. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/276:00 amSFO - MDW
Nonstop4h 05mSouthwest
Sat 11/158:15 amMDW - SFO
Nonstop4h 45mSouthwest
Deal found 8/13$207
This United Airlines deal was found by Cheapflights users on 8/13. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/163:00 pmSFO - ORD
Nonstop4h 24mUnited Airlines
Fri 9/269:13 pmORD - SFO
Nonstop4h 46mUnited Airlines
Deal found 8/13$207
This CheapOair deal was found by Cheapflights users on 8/14. 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 10/245:45 amSFO - MDW
2 stops15h 35mFrontier
Mon 10/276:24 pmMDW - SFO
1 stop7h 50mFrontier
Deal found 8/14$208
This United Airlines deal was found by Cheapflights users on 8/12. 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.
Sat 8/304:55 pmSFO - ORD
Nonstop4h 17mUnited Airlines
Sun 8/316:15 amORD - SFO
Nonstop4h 41mUnited Airlines
Deal found 8/12$208

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 August 14, 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 - MDW

SFOMDW

San Francisco

Sat 11/8

12:35 pm-8:25 pm

1 stop5h 50m

Chicago Midway

Tue 11/11

8:15 am-11:00 am

Nonstop4h 45m

$207

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Thu 9/25

11:00 pm-5:13 am

Nonstop4h 13m

Chicago O'Hare Intl

Wed 10/1

6:15 am-8:53 am

Nonstop4h 38m

$207

San FranciscoChicago

SFO - MDW

SFOMDW

San Francisco

Mon 11/17

6:10 am-12:15 pm

Nonstop4h 05m

Chicago Midway

Wed 11/19

8:15 am-11:00 am

Nonstop4h 45m

$207

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Wed 10/29

7:00 am-1:23 pm

Nonstop4h 23m

Chicago O'Hare Intl

Sun 11/2

5:15 am-8:04 am

Nonstop4h 49m

$207

San FranciscoChicago

SFO - MDW

SFOMDW

San Francisco

Tue 11/4

2:15 pm-10:15 pm

1 stop6h 00m

Chicago Midway

Wed 11/12

8:15 am-11:00 am

Nonstop4h 45m

$207

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Wed 9/3

5:15 am-11:46 am

Nonstop4h 31m

Chicago O'Hare Intl

Thu 9/4

2:25 pm-5:07 pm

Nonstop4h 42m

$207

San FranciscoChicago

SFO - MDW

SFOMDW

San Francisco

Fri 11/14

6:15 am-12:20 pm

Nonstop4h 05m

Chicago Midway

Tue 11/18

8:15 am-11:00 am

Nonstop4h 45m

$207

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Wed 9/10

11:10 pm-5:23 am

Nonstop4h 13m

Chicago O'Hare Intl

Thu 9/25

6:15 am-8:56 am

Nonstop4h 41m

$207

San FranciscoChicago

SFO - MDW

SFOMDW

San Francisco

Thu 9/4

7:15 am-1:20 pm

Nonstop4h 05m

Chicago Midway

Tue 9/9

3:50 pm-6:25 pm

Nonstop4h 35m

$207

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Tue 9/16

3:00 pm-9:24 pm

Nonstop4h 24m

Chicago O'Hare Intl

Fri 9/26

9:13 pm-11:59 pm

Nonstop4h 46m

$207

Flights are sorted by cheapest round-trip flights first.

Deals found on 8/12

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 August 14, 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 August 14, 2025.

The most flights from SFO to USIL are scheduled on a Thursday (92 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (33 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 August 14, 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

Overall

8.0

Comfort

7.8

Boarding

8.1

Crew

8.5

Entertainment

7.0

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

Food

7.1

Overall

8.0

Comfort

7.8

Boarding

8.1

Crew

8.5

Entertainment

7.0

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
4,244 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Overall

8.0

Comfort

7.8

Boarding

8.1

Crew

8.5

Entertainment

7.0

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
8,916 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Overall

8.0

Comfort

7.8

Boarding

8.1

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Overall

8.0

Comfort

7.8

Boarding

8.1

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Frontier
5.8
Fair
3,219 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Overall

8.0

Comfort

7.8

Boarding

8.1

Crew

8.5

Entertainment

7.0

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 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.

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

    To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $80. Southwest flights start at $99 while deals on United Airlines start at $99 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: Fiji Airways (100%), Asiana Airlines (85%), Austrian Airlines (81%).

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

    Looking at all options, your cheapest flight can be booked for $98. While the most popular route (San Francisco - Chicago O'Hare Intl) can be booked for $197 on average our data indicates $898 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 8 airlines flying from San Francisco to Illinois

Discover the top 8 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 August 14, 2025.
AirlineCheapestAverageFlexibilityOn-time
Hawaiian AirlinesCheapest$108Average$288FlexibilityNo cancel feeOn-time85%
FrontierCheapest$118Average$211FlexibilityNo cancel feeOn-time62%
DeltaCheapest$128Average$324FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$133Average$439FlexibilityNo cancel feeOn-time69%
Spirit AirlinesCheapest$143Average$221FlexibilityNo cancel feeOn-time65%
Alaska AirlinesCheapest$177Average$304FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$185Average$337FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$197Average$447FlexibilityNo cancel feeOn-time71%

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