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$66+ Cheap flights from Illinois to San Francisco (SFO)

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 1/10. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SFO
Nov 18 — Nov 251
Tue 11/18
Tue 11/25
1 adult, Economy
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Find flight deals from Illinois to San Francisco

Cheapest flights from Illinois to San Francisco
Explore the most affordable flight options available from Illinois to San Francisco. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 19, 2025.

This Kiwi.com deal was found by Cheapflights users on 10/17. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/127:45 pmSTL - SFO
2 stops24h 04mFrontier
Fri 11/148:09 pmSFO - STL
1 stop10h 58mFrontier
Deal found 10/17$191
This Mytrip deal was found by Cheapflights users on 10/18. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/308:40 pmSTL - SFO
1 stop20h 00mFrontier
Sun 11/25:34 amSFO - STL
1 stop24h 33mFrontier
Deal found 10/18$194
This Frontier deal was found by Cheapflights users on 10/17. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/137:45 pmSTL - SFO
1 stop6h 29mFrontier
Mon 11/175:45 amSFO - STL
1 stop12h 27mFrontier
Deal found 10/17$196
This Kiwi.com deal was found by Cheapflights users on 10/18. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/311:09 pmSTL - SFO
1 stop6h 34mFrontier
Mon 11/34:14 pmSFO - STL
2 stops14h 53mFrontier
Deal found 10/18$202
This Flightnetwork deal was found by Cheapflights users on 10/18. 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 Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/311:09 pmSTL - SFO
1 stop6h 34mFrontier
Sat 11/86:34 amSFO - STL
1 stop24h 33mFrontier
Deal found 10/18$209
This Kiwi.com deal was found by Cheapflights users on 10/16. 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 11/18:40 pmSTL - SFO
1 stop15h 53mFrontier
Sat 11/87:30 pmSFO - STL
2 stops35h 37mFrontier
Deal found 10/16$213
This Kiwi.com deal was found by Cheapflights users on 10/16. 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 11/18:40 pmSTL - SFO
1 stop15h 53mFrontier
Sat 11/156:34 amSFO - STL
2 stops25h 38mFrontier
Deal found 10/16$217
This Kiwi.com deal was found by Cheapflights users on 10/17. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/67:45 pmSTL - SFO
2 stops21h 44mFrontier
Mon 11/106:34 amSFO - STL
1 stop24h 33mFrontier
Deal found 10/17$220
This Kiwi.com deal was found by Cheapflights users on 10/17. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/57:45 pmSTL - SFO
2 stops19h 15mFrontier
Sat 11/86:34 amSFO - STL
1 stop24h 33mFrontier
Deal found 10/17$223
This Kiwi.com deal was found by Cheapflights users on 10/17. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/3012:30 pmMDW - SFO
1 stop28h 10mFrontier
Thu 11/610:11 pmSFO - MDW
2 stops36h 26mFrontier
Deal found 10/17$240
This Alaska Airlines deal was found by Cheapflights users on 10/18. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/93:05 pmORD - SFO
1 stop8h 41mAlaska Airlines
Tue 1/132:52 pmSFO - ORD
1 stop6h 45mAlaska Airlines
Deal found 10/18$240
This Kiwi.com deal was found by Cheapflights users on 10/18. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/16:20 amMDW - SFO
2 stops13h 23mFrontier
Sun 11/28:55 pmSFO - MDW
1 stop17h 57mFrontier
Deal found 10/18$241

Cheap flight deals from Illinois to San Francisco

Keep the following information in mind while searching for Illinois to San Francisco flight deals. Data was last updated October 19, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$191
(Kiwi.com)

One-way from

$66
(Kiwi.com)

Popular in

December

Cheapest in

July

Average price

$321

Good round-trip deal

$294 or less

Good one-way deal

$155 or less
Provider with most accurate pricing for Chicago (CHI)-San Francisco flight deals.
Search Deals
Provider most trusted by Cheapflights users for Chicago (CHI)-San Francisco flights.
Search Deals
From Illinois to San Francisco
Search Deals
One-way flight from Illinois to San Francisco
Search Deals
Highest demand for flights based on searches. 10% potential increase in price ($37 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($7 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 Illinois to San Francisco.
Search Deals
Price to beat on a one-way flight from Illinois to San Francisco.
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Cheapflights Fare Finder

 
Customize your flight search to find flights from Illinois to San Francisco 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 19, 2025.
Use the filters below to find and compare flights from Illinois to San Francisco that are best for you.

Fly from

Illinois

Fly to

San Francisco

Route

Depart

Return

Price

St. LouisSan Francisco

STL - SFO

STLSFO

Lambert-St Louis

Fri 10/31

1:09 pm-5:43 pm

1 stop6h 34m

San Francisco

Mon 11/3

4:14 pm-9:07 am

2 stops14h 53m

$202

St. LouisSan Francisco

STL - SFO

STLSFO

Lambert-St Louis

Thu 10/30

8:40 pm-1:25 pm

2 stops18h 45m

San Francisco

Sun 11/2

8:55 pm-11:24 am

1 stop12h 29m

$248

ChicagoSan Francisco

ORD - SFO

ORDSFO

Chicago O'Hare Intl

Thu 12/18

8:58 pm-8:15 am

1 stop13h 17m

San Francisco

Sat 1/17

6:56 pm-1:10 pm

1 stop16h 14m

$266

ChicagoSan Francisco

ORD - SFO

ORDSFO

Chicago O'Hare Intl

Thu 11/27

6:15 am-9:04 am

Nonstop4h 49m

San Francisco

Tue 12/2

11:44 pm-6:02 am

Nonstop4h 18m

$266

St. LouisSan Francisco

STL - SFO

STLSFO

Lambert-St Louis

Thu 11/13

6:34 am-3:57 pm

2 stops11h 23m

San Francisco

Mon 11/17

1:58 pm-12:46 am

2 stops8h 48m

$274

ChicagoSan Francisco

MDW - SFO

MDWSFO

Chicago Midway

Fri 10/31

9:15 am-11:50 am

Nonstop4h 35m

San Francisco

Sat 11/8

9:25 pm-8:50 am

1 stop9h 25m

$276

DecaturSan Francisco

DEC - SFO

DECSFO

Decatur Arpt

Thu 1/8

9:49 am-3:35 pm

1 stop7h 46m

San Francisco

Mon 1/12

6:45 am-6:01 pm

1 stop9h 16m

$284

ChicagoSan Francisco

MDW - SFO

MDWSFO

Chicago Midway

Fri 10/31

3:00 pm-8:40 pm

1 stop7h 40m

San Francisco

Sat 11/8

6:10 am-3:26 pm

1 stop7h 16m

$286

ChicagoSan Francisco

ORD - SFO

ORDSFO

Chicago O'Hare Intl

Sat 12/20

12:39 pm-8:50 pm

1 stop10h 11m

San Francisco

Wed 12/24

12:10 am-9:25 am

1 stop7h 15m

$286

MolineSan Francisco

MLI - SFO

MLISFO

Moline Quad-City

Wed 3/4

5:22 pm-11:11 pm

1 stop7h 49m

San Francisco

Tue 3/10

11:59 pm-10:04 am

1 stop8h 05m

$289

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/18

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

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

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

Currently, October is the cheapest month in which you can book a flight from Illinois to San Francisco (average of $80). Flying from Illinois to San Francisco in December is currently the most expensive (average of $207). 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 IL to SFO?

Find hourly flight availability from Illinois to San Francisco. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 19, 2025.

It’s optimal to fly from Illinois to San Francisco in the evening. By choosing this option you can save up to 18% on the cost of your flight, compared to a flight at noon.

What is the cheapest day to fly from Illinois to San Francisco?

Use this chart to determine the cheapest time to fly round-trip from Illinois to San Francisco. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Illinois to San Francisco flight should consider departing on Tuesday afternoons when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Illinois to San Francisco

Explore weekly flight availability from Illinois to San Francisco. 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 19, 2025.

The most flights from USIL to SFO are scheduled on a Sunday (89 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (66 on average).

Related info for your journey

Find useful and relevant information for your journey from Illinois to San Francisco. 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 into for flights to San Francisco from Illinois?

    If you book a flight to San Francisco from Illinois, you will be flying to San Francisco, which is the city’s only airport. San Francisco (SFO) is located 11.8 mi from the center of San Francisco.

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

    Frontier, Alaska Airlines, and United Airlines can get you from Illinois to San Francisco in just under 4h 49m. Your travel time can differ by up to 8h 28m. Airlines will cover a distance of 1841 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

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

    The cheapest airline one-way is Frontier, with whom users have recently found tickets for as low as $85. However, be on the lookout for offers from Sun Country Air and Southwest, as they are both options that can get you from Illinois to San Francisco for a low price.

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

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

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

    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 Illinois to San Francisco on time: Air China (92%), ANA (92%), ITA Airways (78%).

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

    While on average a flight from Illinois to San Francisco is generally $1,032, our data shows the cheapest flight currently is $127. When looking at the most popular route, (Chicago O'Hare Intl - San Francisco), you can expect to pay $175 for that flight.

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

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

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

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

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

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

    Currently, October is the cheapest month in which you can book a flight from Illinois to San Francisco (average of $80). Flying from Illinois to San Francisco in December is currently the most expensive (average of $207). 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

Traveling to a place near San Francisco?

Book flights to San Francisco if you plan to visit one of these locations
Roseville
Santa Cruz
Livermore
South San Francisco
Turlock
Antioch
Watsonville
Santa Clara
Manteca
Sunnyvale
Vacaville
Vallejo
Hollister
Foster City
Union City
Fairfield
Burlingame
Redwood City
Lodi
San Mateo

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Illinois to San Francisco

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Top 8 airlines flying from Illinois to San Francisco

Discover the top 8 airlines that operate flights from Illinois to San Francisco. 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 19, 2025.
AirlineCheapestAverageFlexibilityOn-time
Hawaiian AirlinesCheapest$108Average$217FlexibilityNo cancel feeOn-time85%
Sun Country AirCheapest$112Average$374FlexibilityNo cancel feeOn-time83%
FrontierCheapest$123Average$277FlexibilityNo cancel feeOn-time62%
DeltaCheapest$128Average$320FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$138Average$381FlexibilityNo cancel feeOn-time63%
Alaska AirlinesCheapest$188Average$296FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$197Average$451FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$202Average$405FlexibilityNo cancel feeOn-time69%

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