$52+ 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 3/3. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — ORD
Jan 3 — Jan 101
1 adult, Economy
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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
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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 Francisco to Illinois
Cheapest flights from San Francisco to IllinoisExplore 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 December 4, 2025.
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 December 4, 2025.
This Kiwi.com deal was found by Cheapflights users on 12/1. 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 12/106:00 amSFO - STL
1 stop28h 12mFrontier
Thu 12/185:19 pmSTL - SFO
1 stop16h 29mFrontier
Deal found 12/1![Frontier logo]()
$168
This Kiwi.com deal was found by Cheapflights users on 12/1. 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 12/106:00 amSFO - STL
1 stop28h 12mFrontier
Mon 12/151:16 pmSTL - SFO
2 stops33h 55mFrontier
Deal found 12/1![Frontier logo]()
$184
This Kiwi.com deal was found by Cheapflights users on 12/1. 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 12/118:43 amSFO - STL
1 stop25h 29mFrontier
Thu 12/185:19 pmSTL - SFO
1 stop16h 29mFrontier
Deal found 12/1![Frontier logo]()
$185
This Kiwi.com deal was found by Cheapflights users on 12/1. 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 12/106:00 amSFO - STL
1 stop28h 12mFrontier
Sun 12/1410:44 pmSTL - SFO
1 stop11h 04mFrontier
Deal found 12/1![Frontier logo]()
$191
This Kiwi.com deal was found by Cheapflights users on 12/1. 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 12/118:43 amSFO - STL
1 stop25h 29mFrontier
Mon 12/151:16 pmSTL - SFO
2 stops33h 55mFrontier
Deal found 12/1![Frontier logo]()
$201
This Kiwi.com deal was found by Cheapflights users on 12/1. 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 12/106:00 amSFO - STL
1 stop28h 12mFrontier
Tue 12/163:30 pmSTL - SFO
2 stops27h 21mFrontier
Deal found 12/1![Frontier logo]()
$204
This Alaska Airlines deal was found by Cheapflights users on 12/3. 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 12/177:00 amSFO - ORD
1 stop10h 54mAlaska Airlines
Sun 1/182:06 pmORD - SFO
2 stops9h 52mAlaska Airlines
Deal found 12/3![Alaska Airlines logo]()
$274
This Delta deal was found by Cheapflights users on 12/2. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/2512:10 amSFO - MDW
1 stop8h 56mDelta
Fri 1/91:49 pmMDW - SFO
1 stop9h 10mDelta
Deal found 12/2![Delta logo]()
$275
This Kiwi.com deal was found by Cheapflights users on 12/2. 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.
Wed 12/249:30 pmSFO - ORD
1 stop16h 19mFrontier
Thu 1/85:50 amORD - SFO
1 stop9h 28mFrontier
Deal found 12/2![Frontier logo]()
$275
This Southwest deal was found by Cheapflights users on 12/3. 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.
Sat 12/275:45 amSFO - MDW
Nonstop4h 00mSouthwest
Tue 1/68:10 amMDW - SFO
2 stops8h 45mSouthwest
Deal found 12/3![Southwest logo]()
$276
This Kiwi.com deal was found by Cheapflights users on 12/3. 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 12/106:00 amSFO - ORD
2 stops38h 38mFrontier
Sat 12/131:24 pmORD - SFO
1 stop10h 26mFrontier
Deal found 12/3![Frontier logo]()
$276
This Kiwi.com deal was found by Cheapflights users on 12/3. 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 12/136:00 amSFO - ORD
1 stop27h 42mFrontier
Mon 12/158:36 amORD - SFO
2 stops34h 15mFrontier
Deal found 12/3![Frontier logo]()
$277
Find 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 December 4, 2025.
Most accurate provider | eDreams 3 stars |
|---|---|
Most trusted provider | eDreams 3 stars |
Round-trip from | $132 (Kiwi.com) |
One-way from | $52 (Trip.com) |
Popular in | November |
Cheapest in | February |
Average price | $434 |
Good round-trip deal | $342 or less |
Good one-way deal | $168 or less |
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 December 4, 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 FranciscoSt. Louis
SFO - STL
SFOSTL
San Francisco
Fri 2/6
6:15 am-6:44 pm
1 stop10h 29m
Lambert-St Louis
Sun 2/8
9:32 pm-5:54 pm
2 stops22h 22m
$188
San FranciscoSt. Louis
SFO - STL
SFOSTL
San Francisco
Fri 1/30
10:30 am-11:25 pm
2 stops10h 55m
Lambert-St Louis
Tue 2/3
3:31 pm-11:30 pm
2 stops9h 59m
$254
San FranciscoSt. Louis
SFO - STL
SFOSTL
San Francisco
Tue 1/6
5:00 am-1:16 pm
1 stop6h 16m
Lambert-St Louis
Tue 1/13
5:00 pm-8:01 pm
Nonstop5h 01m
$260
San FranciscoChicago
SFO - MDW
SFOMDW
San Francisco
Thu 12/25
12:10 am-11:06 am
1 stop8h 56m
Chicago Midway
Wed 1/7
7:16 pm-11:47 pm
1 stop6h 31m
$275
San FranciscoChicago
SFO - MDW
SFOMDW
San Francisco
Thu 1/1
6:10 am-12:15 pm
Nonstop4h 05m
Chicago Midway
Thu 1/8
5:05 am-11:50 am
1 stop8h 45m
$279
San FranciscoChicago
SFO - ORD
SFOORD
San Francisco
Sat 1/10
3:15 pm-9:32 pm
Nonstop4h 17m
Chicago O'Hare Intl
Mon 1/12
6:29 pm-9:30 pm
Nonstop5h 01m
$279
San FranciscoSt. Louis
SFO - STL
SFOSTL
San Francisco
Fri 2/6
6:25 am-4:55 pm
1 stop8h 30m
Lambert-St Louis
Sun 2/8
6:45 am-9:46 am
Nonstop5h 01m
$285
San FranciscoSt. Louis
SFO - STL
SFOSTL
San Francisco
Fri 2/6
10:30 am-11:23 pm
2 stops10h 53m
Lambert-St Louis
Sun 2/8
3:31 pm-11:30 pm
2 stops9h 59m
$285
San FranciscoSt. Louis
SFO - STL
SFOSTL
San Francisco
Fri 1/23
10:30 am-11:23 pm
2 stops10h 53m
Lambert-St Louis
Fri 1/30
6:10 am-3:58 pm
2 stops11h 48m
$285
San FranciscoSt. Louis
SFO - STL
SFOSTL
San Francisco
Thu 2/5
11:00 pm-5:11 am
Nonstop4h 11m
Lambert-St Louis
Mon 2/9
4:15 pm-10:58 pm
1 stop8h 43m
$285
Showing 1-10 of 60 results
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, December is the cheapest month in which you can book a flight from San Francisco to Illinois (average of $110). Flying from San Francisco to Illinois in March is currently the most expensive (average of $194). 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 December 4, 2025.
It’s optimal to fly from San Francisco to Illinois in the evening. By choosing this option you can save up to 25% on the cost of your flight, compared to a flight in the afternoon.
What is the cheapest day to fly from San Francisco to Illinois?
Use this chart to determine the cheapest time to fly round-trip from San Francisco to Illinois. Price data was last updated on December 16, 2024.
Travelers seeking maximum savings on their San Francisco to Illinois flight should consider departing on Saturday afternoons when fares are most often at their lowest. Monday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
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 December 4, 2025.
The most flights from SFO to USIL are scheduled on a Wednesday (67 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (41 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 December 4, 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.
Comfort
7.8
Overall
8.0
Boarding
8.1
Crew
8.5
Food
7.1
Entertainment
7.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Nov 2025
LAX - LIH
Comfort
7.8
Overall
8.0
Boarding
8.1
Crew
8.5
Food
7.1
Entertainment
7.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Nov 2025
LAX - LIH
Comfort
7.8
Overall
8.0
Boarding
8.1
Crew
8.5
Food
7.1
Entertainment
7.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Nov 2025
LAX - LIH
Comfort
7.8
Overall
8.0
Boarding
8.1
Crew
8.5
Food
7.1
Entertainment
7.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Nov 2025
LAX - LIH
Comfort
7.8
Overall
8.0
Boarding
8.1
Crew
8.5
Food
7.1
Entertainment
7.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Nov 2025
LAX - LIH
Comfort
7.8
Overall
8.0
Boarding
8.1
Crew
8.5
Food
7.1
Entertainment
7.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Nov 2025
LAX - LIH
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.
Browse thousands of different options on Cheapflights for your next trip
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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.
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 December 4, 2025.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$108 | Average$288 | FlexibilityNo cancel fee | On-time85% | |
| Cheapest$128 | Average$238 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$128 | Average$316 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$133 | Average$468 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$185 | Average$352 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$196 | Average$332 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$197 | Average$466 | FlexibilityNo cancel fee | On-time71% |