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$55+ 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 5/1. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — ORD
Feb 25 — Mar 41
Tue 2/25
Tue 3/4
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 February 20, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$204
(Expedia)

One-way from

$55
(Frontier)

Popular in

December

Cheapest in

February

Average price

$297

Good round-trip deal

$321 or less

Good one-way deal

$181 or less
Provider with most accurate pricing for San Francisco-Chicago (CHI) flight deals.
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Provider most trusted by Cheapflights users for San Francisco-Chicago (CHI) flights.
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From San Francisco to Illinois
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One-way flight from San Francisco to Illinois
Search Deals
Highest demand for flights based on searches. 5% potential increase in price ($19 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 February 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 February 20, 2025.

This FlightHub deal was found by Cheapflights users on 2/19. 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 3/612:15 amSFO - ORD
1 stop14h 11mFrontier
Sat 3/82:48 pmORD - SFO
1 stop10h 01mFrontier
Deal found 2/19$203
This Expedia deal was found by Cheapflights users on 2/18. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/238:19 pmSFO - ORD
1 stop6h 45mMultiple Airlines
Fri 3/286:56 pmORD - SFO
Nonstop4h 59mMultiple Airlines
Deal found 2/18$204
This Trip.com deal was found by Cheapflights users on 2/19. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/3010:59 pmSFO - MDW
1 stop28h 32mFrontier
Sat 4/512:58 pmMDW - SFO
1 stop10h 32mFrontier
Deal found 2/19$206
This Southwest deal was found by Cheapflights users on 2/18. 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.
Wed 4/237:35 pmSFO - MDW
1 stop7h 40mSouthwest
Tue 4/2911:25 amMDW - SFO
Nonstop4h 30mSouthwest
Deal found 2/18$207
This Alaska Airlines deal was found by Cheapflights users on 2/20. 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 3/1210:46 amSFO - ORD
Nonstop4h 12mAlaska Airlines
Thu 3/137:00 pmORD - SFO
Nonstop5h 10mAlaska Airlines
Deal found 2/20$207
This United Airlines deal was found by Cheapflights users on 2/19. 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.
Sun 5/412:25 amSFO - ORD
Nonstop4h 22mUnited Airlines
Fri 5/92:25 pmORD - SFO
Nonstop5h 01mUnited Airlines
Deal found 2/19$218
This American Airlines deal was found by Cheapflights users on 2/20. 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.
Mon 3/246:00 pmSFO - ORD
1 stop9h 04mAmerican Airlines
Thu 3/278:20 pmORD - SFO
Nonstop4h 54mAmerican Airlines
Deal found 2/20$227
This Delta deal was found by Cheapflights users on 2/20. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/1712:30 amSFO - MDW
1 stop7h 15mDelta
Fri 3/282:55 pmMDW - SFO
1 stop9h 50mDelta
Deal found 2/20$257
This Delta deal was found by Cheapflights users on 2/20. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/1612:47 amSFO - ORD
1 stop5h 48mDelta
Sun 4/206:35 amORD - SFO
1 stop6h 32mDelta
Deal found 2/20$257
This Trip.com deal was found by Cheapflights users on 2/20. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/37:47 pmSFO - STL
1 stop11h 19mFrontier
Mon 4/76:51 pmSTL - SFO
2 stops16h 29mFrontier
Deal found 2/20$272
This Hawaiian Airlines deal was found by Cheapflights users on 2/20. 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 3/2011:52 amSFO - ORD
Nonstop4h 24mHawaiian Airlines
Mon 3/246:56 pmORD - SFO
Nonstop4h 59mHawaiian Airlines
Deal found 2/20$277
This Expedia deal was found by Cheapflights users on 2/20. 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.
Mon 4/1410:35 amSFO - STL
2 stops11h 24mMultiple Airlines
Wed 4/166:51 pmSTL - SFO
1 stop7h 53mMultiple Airlines
Deal found 2/20$287

Find flights from San Francisco to Illinois within your budget

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 February 20, 2025.

Fly from

San Francisco

Fly to

Illinois

Route

Depart

Return

Price

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Sun 3/23

8:19 pm-5:04 am

1 stop6h 45m

Chicago O'Hare Intl

Thu 3/27

6:56 pm-9:55 pm

Nonstop4h 59m

$204

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Wed 3/5

10:59 pm-5:10 am

1 stop28h 11m

Chicago O'Hare Intl

Sun 3/9

6:45 am-1:33 pm

1 stop8h 48m

$205

San FranciscoChicago

SFO - MDW

SFOMDW

San Francisco

Sun 3/30

10:59 pm-5:31 am

1 stop28h 32m

Chicago Midway

Sat 4/5

12:58 pm-9:30 pm

1 stop10h 32m

$206

San FranciscoChicago

SFO - MDW

SFOMDW

San Francisco

Wed 4/23

7:35 pm-5:15 am

1 stop7h 40m

Chicago Midway

Tue 4/29

11:25 am-1:55 pm

Nonstop4h 30m

$207

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Tue 3/18

10:46 am-4:58 pm

Nonstop4h 12m

Chicago O'Hare Intl

Thu 3/27

6:56 pm-9:55 pm

Nonstop4h 59m

$207

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Mon 4/14

12:08 am-6:30 am

Nonstop4h 22m

Chicago O'Hare Intl

Fri 4/18

8:45 am-11:28 am

Nonstop4h 43m

$208

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Mon 4/28

11:59 pm-6:17 am

Nonstop4h 18m

Chicago O'Hare Intl

Thu 5/1

8:15 pm-11:09 pm

Nonstop4h 54m

$217

San FranciscoChicago

SFO - ORD

SFOORD

San Francisco

Wed 4/16

6:05 am-5:55 pm

2 stops9h 50m

Chicago O'Hare Intl

Mon 4/21

6:55 pm-11:59 pm

1 stop7h 04m

$225

San FranciscoChicago

SFO - MDW

SFOMDW

San Francisco

Mon 3/17

12:30 am-9:45 am

1 stop7h 15m

Chicago Midway

Fri 3/28

2:55 pm-10:45 pm

1 stop9h 50m

$257

San FranciscoSt. Louis

SFO - STL

SFOSTL

San Francisco

Thu 4/3

7:47 pm-9:06 am

1 stop11h 19m

Lambert-St Louis

Mon 4/7

6:51 pm-9:20 am

2 stops16h 29m

$272

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/20

Showing 1-10 of 59 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.

Travel insights for flights from San Francisco to Illinois

Get recent, data-driven insights about flights from San Francisco to Illinois including ideal travel times, pricing trends, and more.

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 February 20, 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 February 20, 2025.

The most flights from SFO to USIL are scheduled on a Monday (56 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (19 on average).

Rainfall in Illinois by month

Plan your trip to Illinois by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Illinois ranges from 1.7 - 4.9 inches per month. August is typically the wettest month, when rainfall can reach 4.9 in. January is typically the driest time to visit Illinois when rainfall is around 1.7 in.

Temperature in Illinois by month

Plan your trip to Illinois by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Illinois, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 73.4 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 23.0 F).

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 February 20, 2025.
Get a feel of what it's like to fly with Southwest, Alaska Airlines and Delta 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.
Southwest
8.1
Very good
4,411 reviews

Boarding

8.2

Entertainment

7.6

Comfort

8.1

Crew

8.7

Food

7.1

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Southwest
8.1
Very good
4,411 reviews
Southwest
8.1
Very good
4,411 reviews

Boarding

8.2

Entertainment

7.6

Comfort

8.1

Crew

8.7

Food

7.1

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Alaska Airlines
8.0
Very good
9,697 reviews
Southwest
8.1
Very good
4,411 reviews

Boarding

8.2

Entertainment

7.6

Comfort

8.1

Crew

8.7

Food

7.1

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Delta
8.0
Very good
8,219 reviews
Southwest
8.1
Very good
4,411 reviews

Boarding

8.2

Entertainment

7.6

Comfort

8.1

Crew

8.7

Food

7.1

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Hawaiian Airlines
7.9
Good
2,317 reviews
Southwest
8.1
Very good
4,411 reviews

Boarding

8.2

Entertainment

7.6

Comfort

8.1

Crew

8.7

Food

7.1

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

JetBlue
7.4
Good
3,070 reviews
Southwest
8.1
Very good
4,411 reviews

Boarding

8.2

Entertainment

7.6

Comfort

8.1

Crew

8.7

Food

7.1

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

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 $55. Southwest flights start at $99 while deals on Alaska 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: Asiana Airlines (97%), Iberia (94%), Royal Jordanian (94%).

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

    Looking at all options, your cheapest flight can be booked for $108. While the most popular route (San Francisco - Chicago O'Hare Intl) can be booked for $161 on average our data indicates $889 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 February 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$74Average$223FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$112Average$241FlexibilityNo cancel feeOn-time65%
Alaska AirlinesCheapest$168Average$319FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$185Average$464FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$207Average$464FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$208Average$416FlexibilityNo cancel feeOn-time63%
DeltaCheapest$236Average$348FlexibilityNo cancel feeOn-timeN/A
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