$48 Find Cheap Flights from San Francisco to Illinois

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from San Francisco to Illinois departing on 3/10. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Illinois

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from San Francisco to Illinois.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from San Francisco to Illinois.
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Flight Deals

Cheap Flights from San Francisco to Illinois

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Chicago
Chicago1 stop$247
Moline
Moline1 stop$309
Peoria
Peoria1 stop$359
Bloomington
Bloomington1 stop$459
Champaign
Champaign1 stop$398
St. Louis
St. Louis1 stop$148
Decatur
Decatur1 stop$395
Paducah
Paducah1 stop$687
Chicago
Chicago1 stop$247
Moline
Moline1 stop$309
Peoria
Peoria1 stop$359
Bloomington
Bloomington1 stop$459
Champaign
Champaign1 stop$398
St. Louis
St. Louis1 stop$148
Decatur
Decatur1 stop$395
Paducah
Paducah1 stop$687

Book Cheap San Francisco to Illinois Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from San Francisco to Illinois that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from San Francisco to Illinois

Wed, Feb 25 - Sat, Feb 28
Frontier Logo
7:20 am - 3:53 pm
SFO
-
STL
6h 33m
1 stop
Frontier Logo
2:51 pm - 12:28 am
STL
-
SFO
11h 37m
1 stop
$148Frontier
Fri, Feb 27 - Mon, Mar 2
Frontier Logo
8:48 am - 1:56 pm
SFO
-
STL
27h 08m
1 stop
Frontier Logo
10:11 pm - 6:20 pm
STL
-
SFO
22h 09m
1 stop
$157Frontier
Tue, Mar 31 - Sat, Apr 4
Southwest Logo
2:25 pm - 12:05 am
SFO
-
MDW
7h 40m
1 stop
Southwest Logo
9:40 pm - 12:20 am
MDW
-
SFO
4h 40mnonstop
$247Southwest
Fri, Feb 20 - Tue, Feb 24
United Airlines Logo
11:59 pm - 6:19 am
SFO
-
ORD
4h 20mnonstop
United Airlines Logo
6:17 pm - 9:20 pm
ORD
-
SFO
5h 03mnonstop
$250United Airlines
Sat, Feb 21 - Tue, Feb 24
United Airlines Logo
10:50 pm - 5:12 am
SFO
-
ORD
4h 22mnonstop
United Airlines Logo
12:46 pm - 3:51 pm
ORD
-
SFO
5h 05mnonstop
$253United Airlines
Fri, Feb 20 - Sat, Feb 28
Delta Logo
12:40 am - 11:03 am
SFO
-
MDW
8h 23m
1 stop
Delta Logo
1:28 pm - 6:36 pm
MDW
-
SFO
7h 08m
1 stop
$257Delta
Wed, Mar 4 - Tue, Mar 10
Delta Logo
5:45 am - 5:37 pm
SFO
-
MDW
9h 52m
1 stop
Delta Logo
10:45 am - 5:36 pm
MDW
-
SFO
8h 51m
1 stop
$259Delta
Wed, Feb 18 - Sun, Feb 22
Southwest Logo
9:30 pm - 9:00 am
SFO
-
MDW
9h 30m
1 stop
Southwest Logo
7:55 am - 10:55 am
MDW
-
SFO
5h 00mnonstop
$260Southwest
Wed, Feb 25 - Sat, Feb 28
American Airlines Logo
2:27 pm - 11:28 pm
SFO
-
MLI
7h 01m
1 stop
American Airlines Logo
3:33 pm - 10:11 pm
MLI
-
SFO
8h 38m
1 stop
$309American Airlines
Wed, Feb 25 - Sat, Feb 28
American Airlines Logo
11:30 am - 11:37 pm
SFO
-
MLI
10h 07m
2 stops
American Airlines Logo
12:44 pm - 8:56 pm
MLI
-
SFO
10h 12m
1 stop
$314American Airlines
Booking Insights

KAYAK's insights & trends for San Francisco to Illinois flights

Get data-powered insights and trends into flights from San Francisco to Illinois to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest San Francisco to Illinois flight route?

Data is based on round-trip flight searches on KAYAK over the past month.

The cheapest ticket to Illinois from San Francisco found in the last 72 hours was to Chicago, at $250 round-trip. The most popular route is from San Francisco (SFO) to Chicago O'Hare Intl Airport (ORD), and the cheapest round-trip airline ticket found on this route in the last 72 hours was $250.

Can I save money by flying with a layover from San Francisco to Illinois?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of $334, prices are generally cheapest when you fly direct.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from San Francisco to Illinois, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from San Francisco to Illinois is February, when tickets cost $289 (return) on average. On the other hand, the most expensive months are November and December, when the average cost of round-trip tickets is $437 and $420 respectively.

What’s the cheapest day of the week to fly from San Francisco to Illinois?

The average price of all round-trip flights from San Francisco to Illinois clicked on KAYAK for each day over the last 12 months.

If your flying dates are flexible, you should consider flying to Illinois on a Wednesday, as we generally find the cheapest rates on that day for this route. On the other hand, Sunday is the most expensive day to fly from San Francisco to Illinois. For your return ticket, we recommend flying on a Thursday and avoiding Sundays for the best deals.

How far in advance should I book a flight from San Francisco to Illinois?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from San Francisco to Illinois, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from San Francisco to Illinois, you should book around 4 weeks before departure, which saves you about 47% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 10 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$48
Best time to beat the crowds with an average 5% drop in price.
Most popular time to fly with an average 8% increase in price.
Flight from San Francisco to St. Louis

FAQs - booking Illinois flights

  • How does KAYAK find such low prices on flights from San Francisco to Illinois?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from San Francisco to Illinois.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from San Francisco to Illinois?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from San Francisco to Illinois is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from San Francisco to Illinois?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly from San Francisco to Illinois with an airline and back with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from San Francisco to Illinois?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying from San Francisco to Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • What is the cheapest time of day to fly to Illinois?

    The cheapest time of day to fly to Illinois is generally at night, when round-trip flights cost $410 on average. Morning departures are around 5% more expensive than evening flights, on average. The most expensive time of day to fly to Illinois is generally in the afternoon, which is peak travel time and where the average cost of a ticket is $458.

Reviews of the top 5 airlines serving from San Francisco to Illinois

 
See real verified KAYAK customer reviews for airlines flying from San Francisco to Illinois. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from San Francisco to Illinois? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
Alaska AirlinesOverall score based on 11808 reviews
7.0Entertainment
7.1Food
7.8Comfort
8.5Crew
8.1Boarding
Airline reviews

The stewardess are very nice and pleasant, Someone onboard had a medical attention, and they attended that person non-stop all throughout the flight, and yet, did not forget to serve and help other passengers.

10.0 ExcellentAnonymous, Jan 2026
SFO - MCO
Read more Alaska Airlines reviews

The stewardess are very nice and pleasant, Someone onboard had a medical attention, and they attended that person non-stop all throughout the flight, and yet, did not forget to serve and help other passengers.

The Alaska Airlines app made it very difficult to find my boarding pass. It was very frustrating to use! The flight itself was flawless.

The flight was excellent and very friendly and helpful staff. Will travel again and recommend to friends. Thank you

Did not have In flight service on my round trip due to turbulence. I did not partake in In flight entertainment. Flight descending into LAX was very turbulent. It would have been nice if the pilot communicated with us during that rough descent into LAX to ease the minds of some of us more nervous flyers.

They canceled my flight with only a couple hours before checking in at the airport and offered no alternatives to get home.

I had entered my TSA pre number when I bought the ticket but TSA pre was not on my boarding pass. I went to find an agent at check in and there was only one agent one duty for first class and a line of people waiting for check in/baggage with no agent manning that area.

Comfort level was below par. Food selection was non-existent. Paying $35 for 1st bag is never appreciated. I will not fly them again. I am actually trying to change my return flight.

The flight attendants were excellent and I was in the back of the plane. Much much better than recent JetBlue experiences on that route and better than Delta on that route.

I’m not sure there is anything that can be improved, even the cost was fantastic.

Poor. They should have given me a row with more room and instead they put me in a middle seat with two strangers next to me

All good except once again bags took an hour at Midway Airport Happens all the time. Ridiculous

Great flight but super high price. Glad it was a business trip and not personal

The seats were comfortable, and the boarding process was pretty smooth.

3 hour delay. Had to change plans and was still delayed.

We got exit row seats both flights. Everything was running on time

The boarding and seat assignment system no longer works for me, but I know it is being replaced. Otherwise, I am good with the overall experience.

The lead steward kept singing about "San Francisco" and hotel California---more annoying than humorous....needs work. Flight was smooth and on time.

San Diego airport is brand new, spacious, airy and very smooth checkin at SW baggage drop.

It was rough. The staff was unprofessional, the choice of on board drinks terrible, it was cramped in space at every airport, they always ran out of overhead bin space so they pressured people to check bags for free or we couldn’t leave on the plane— so I did check my bag to help, and they nearly lost my bag. My bag did not arrive on the luggage belt, another man on my flight and I had to waste our time going to the baggage office to search for our bags. I would only fly southwest again if it was my last choice. Also, my flights were consistently delayed over and over again— at one point they straight up told us we were waiting for the pilot to arrive.

Crew could have been friendlier, maybe I'm spoiled by SW crews. In flight wifi was good. Would be nice to have more food offerings on a 4 plus hour flight

The flight crew where really good. Better then the crew from BNE to SFO

Food should be changed in menu Many muslims travels in this airlime they need to add one Halal meal

left on time, reasonable boarding process arrived early luggage came out quickly

Some flight attendants were great others were cranky. Seats were very tight and sitting on an aisle was very hard as the carts and people walking constantly bumped shoulder and arm.

Pushed back only to get deplaned due to a tire damaged by ground crew. They did at least go pretty fast. The bathrooms should be banned under the Geneva convention. No room to even sit straight on the toilet. The under-seat entertainment units block what little leg room there is.

United airlines has the best customer experience from booking to arrival. I always fly United airlines. The mileage program is excellent

from SFO-> FRA flight, AVML meal was significantly less compared to regular meal, especially no Desert, no Bread, no sides.

This was an older airplane. The cabin was constantly warm to hot throughout the 10 hour flight and there were no vents to personalize air flow. Also since it was an older plane, the material and comfort of the chairs were very uncomfortable. I left my flight with major soreness on my tailbone.

Older aircraft, no meal, only food was for purchase. Not impressed United.

Not pleasant trip cross country when the entertainment and WiFi system not working. No entertainment for entirety of route. Staff was rather nonchalant in that they dismissed the problem due to age of plane. It would have been nice to know this up front so I could have come prepared to read or download movies before boarding Coincidentally or not, there was a similar issue with the entertainment system on my previous flight I took on my fist leg of the trip. There are no seat TVs, so you must rely on the app when it works. United can do better. Also, what use it it to pay for boarding group 2 when half of the passengers are in the same line as you?

Pilot navigated severe weather/snow storm with skill. Described his intentions clearly

Little warm on the plane and delayed for an hour

So excited very proud first of all I wanna thank kayak all updates very professional and fast alart And amazing cabin crew so nice to me they deserve big salute

The boarding process needs to be fixed. The zone don't work, especially when there is hardly anyone in zones 3, 4,and 5, leaving the majority of the passengers backed up in the aisle, especially because passengers seated near the front are blocking passengers who are seated in the rear of the plane. It would also help if the size of carry on bags was more strictly enforced.

Awful. They won’t help me with anything. I booked on American but they abdicated to Iberia. The ticket was overpriced. Everything negative

I enjoyed the extra leg room compared to other airlines. The first stewards made my daughter’s birthday special by giving her an extra snack. Then the last one coming home from Chicago to Appleton made our night really enjoyable Thanks for making our trip enjoyable

It was good..clean, comfy seat. Friendly warm welcoming crew. Was able to check my cabin luggage at the gate which I was able to pickup in a decent time from baggage claim. The app gave all updates from delays to baggage claim info. Overall smooth flight.

Mostly good. Flight was crowded but Airline personnel were very friendly & accommodating. It would be good to have savory snacks rather than just sweet Biscoff cookies.

It was a typical flight. We had a delay which seems to be the normality now. And we had no in flight service due to conditions.

After we landed we sat on the tarmac for 1.5 hours waiting to get to our gate. Ridiculous.

Good for a budget airline! It was easy to get on, staff was really nice. Can’t say anything about the food or entertainment because it wasn’t available, which is fine.

It was ok. It was expensive to check 2 bags ($75.00 per bag), and then it took a long time to wait for shuttle to take us from one terminal to the terminal where the plane was taking off at LAX. And all of this for a flight where we had to pay for any food or drink that was not water.

This company socks. It's fraud. They canceled our flight yesterday, and today we were late because of a really long line at the check in bag. At the rebook station, there was ton of people. The workers were all rude. I am gonna make a report to FTC.

When I wanted to check in 3 hours prior to boarding time, the employees mentioned “a little over an hour delay” so I waited for an hour then I went to go look for food in the terminal and most people from that flight were in the same area looking for food. Finally I decided after food to check to see if it’s anytime closer and now it’s 2 mins until boarding closes?! What are you kidding me? I didn’t receive anything via sms about boarding now nor via email or on the intercom. I luckily made it through, barely, and then there’s no room for my carry on mind you I’m in the very first row so I had to place my purse in one further row back and my carry on sections down. Not sure who pays for better seats to get your stuff placed all over the plane but that was the worst experience I’ve ever had flying with anyone.

The single worst check in experience I could imagine. I’ll never do any business with Frontier or any affiliated company

Too many extra fees, uncomfortable, little leg room. Will not recommend this airline.

This airline sucks. They offer low rates then charge you for everything, the app does not work well, the seats are the most uncomfortable. Maintenance issues on the flight, and you still have to sit through their credit card commercials. People are nice enough but does not make up for overall poor experience.

Severe turbulence. Captain never came on to reassure passengers after things settled down.

We were delayed three times ,and that destroyed my plans, and reservations

Cancelled flight after I arrived at airport after 75 min drive and parking. Next flight was 4 days in the future. Had to scramble and buy a much more expensive flight on another carrier.

Everything you need to know for your flight from San Francisco to Illinois

Information on your arrival and departure airports