$59 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 2/5. 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
Chicago2 stops$259
Moline
Moline1 stop$309
Peoria
Peoria1 stop$253
Bloomington
Bloomington1 stop$481
Champaign
Champaign2 stops$419
Springfield
Springfield1 stop$465
St. Louis
St. Louis1 stop$131
Decatur
Decatur1 stop$383
Chicago
Chicago2 stops$259
Moline
Moline1 stop$309
Peoria
Peoria1 stop$253
Bloomington
Bloomington1 stop$481
Champaign
Champaign2 stops$419
Springfield
Springfield1 stop$465
St. Louis
St. Louis1 stop$131
Decatur
Decatur1 stop$383

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 4 - Mon, Feb 9
Frontier Logo
2:08 pm - 9:06 pm
SFO
-
STL
28h 58m1 stop
Frontier Logo
9:45 pm - 6:20 pm
STL
-
SFO
22h 35m1 stop
$131Frontier
Wed, Jan 14 - Wed, Jan 21
Frontier Logo
2:24 pm - 12:40 pm
SFO
-
STL
20h 16m1 stop
Frontier Logo
3:46 pm - 11:41 pm
STL
-
SFO
9h 55m1 stop
$133Frontier
Wed, Apr 29 - Mon, May 4
Alaska Airlines Logo
7:15 am - 7:03 pm
SFO
-
ORD
9h 48m1 stop
Alaska Airlines Logo
3:52 pm - 11:48 pm
ORD
-
SFO
9h 56m1 stop
$259Alaska Airlines
Sat, Feb 7 - Wed, Feb 11
Southwest Logo
10:25 am - 4:20 pm
SFO
-
MDW
3h 55mnonstop
Southwest Logo
10:05 am - 2:55 pm
MDW
-
SFO
6h 50m1 stop
$261Southwest
Tue, Jan 20 - Thu, Jan 29
Alaska Airlines Logo
9:16 am - 2:29 pm
SFO
-
ORD
27h 13m1 stop
Alaska Airlines Logo
3:44 pm - 10:47 pm
ORD
-
SFO
9h 03m1 stop
$262Alaska Airlines
Wed, Feb 11 - Wed, Feb 18
Southwest Logo
5:30 am - 6:45 pm
SFO
-
MDW
11h 15m2 stops
Southwest Logo
1:15 pm - 8:15 pm
MDW
-
SFO
9h 00m2 stops
$262Southwest
Wed, May 6 - Sat, May 9
United Airlines Logo
10:45 pm - 5:15 am
SFO
-
ORD
4h 30mnonstop
United Airlines Logo
3:45 pm - 6:38 pm
ORD
-
SFO
4h 53mnonstop
$263United Airlines
Wed, Jan 21 - Thu, Jan 22
United Airlines Logo
11:56 pm - 6:25 am
SFO
-
ORD
4h 29mnonstop
United Airlines Logo
2:40 pm - 5:36 pm
ORD
-
SFO
4h 56mnonstop
$265United Airlines
Wed, Jan 28 - Thu, Feb 19
American Airlines Logo
12:17 am - 10:30 am
SFO
-
MLI
8h 13m1 stop
American Airlines Logo
3:33 pm - 11:00 pm
MLI
-
SFO
9h 27m1 stop
$309American Airlines
Thu, Jan 29 - Thu, Feb 19
American Airlines Logo
9:10 am - 10:23 pm
SFO
-
MLI
11h 13m2 stops
American Airlines Logo
3:33 pm - 10:07 pm
MLI
-
SFO
8h 34m1 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 $238 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 $263.

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 $359, 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 $283 (return) on average. On the other hand, the most expensive months are December and November, when the average cost of round-trip tickets is $459 and $437 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$59
Best time to beat the crowds with an average 10% drop in price.
Most popular time to fly with an average 13% 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 $459.

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 11569 reviews
8.1Boarding
7.1Food
7.8Comfort
8.5Crew
7.0Entertainment
Airline reviews

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.

8.0 ExcellentMarc, Dec 2025
SFO - SLC
Read more Alaska Airlines reviews

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

Flight crew and flight were good. But it departed two hours late.

The ground crew did not supply drink or snacks during the layover in SFO. So there weren't many options. Otherwise, it was all great.

I love a red eye flight. No lines to wait in. Lots of turbulence on the flight and a very shaky landing.

Flight was delayed 14 hours! We missed an entire day of our vacation and had to pay for hotel that we didn’t use

Could not check in online. Called airline twice, thinking Hawaiian Airlines could check me in during phone call. NO. In 2nd phone call, Customer Service explained that due to “transition period” of Hawaiian Airlines/Alaska Airlines merger, I could only check in at the airport. In addition, flight to Kahului was late at arrival gate; I made connection to Lihue but my bag did not, so I had to return to Lihue airport a couple hours after my arrival to retrieve the bag.

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

Ever since Southwest starting charging for bags, passengers don't want to pay to check their bags, so the gate agents have to beg people to check their roller bags now because there's "not enough space". This was a terrible business move by Southwest.

Sacrament staff are always polite and helpful. Airport is easy to maneuver and boarding is straightforward.

Excellent. Would encourage Southwest to keep current boarding procedures with free style seating. Makes for a fantastic experience

As always, the entire Southwest experience was wonderful, from online booking to flight to baggage retrieval. Very grateful.

The weather could have been better. There was a 40 minute ATC delay in SFO because of marine fog and a micro cell storm delayed landing and take-off at Nashville. The gate was changed 5 minutes from boarding from gate B3 to gate C23 at Nashville airport.

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?

My experience on this United Airlines flight was highly uncomfortable, primarily due to two issues: Cabin Temperature: The temperature on the Boeing 737 MAX 8 was unacceptably high, feeling consistently around 80 degrees throughout the flight. This made sleeping impossible and significantly detracted from the experience. Seating Arrangement: Being stuck in a middle seat for a six-and-a-half-hour overnight flight compounded the discomfort. Moving forward, I will always purchase a seat assignment to avoid this situation.

Premium Plus is a really good idea for longer flights

Same as last comment. Food sucks. Quality. Not surprising most people have no clue about nourishment Clearly

We were in business class. the angled seats in that class do not have a real window view & the placement of the controls are bad. But we knew that. But the food options were mediocre. The taste was fine, but the size was for a child. It’s just really feels like United is skimping on everything. Even when we were in the Polaris lounge they did not have diet sodas. They said they were out no Coke zero no Diet Coke, etc. I do not think the portion of nuts they serve on the plane could get any smaller. Really a minimal service and offer for what you’re paying for in business.

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.

Terrible. Flight delayed for more than 8 hours with only a $12 meal voucher provided for the inconvenience. The airplane did not have breaks on arrival yet they still made us go through the motions and board on time knowing we could not take off then sit for 40+ minutes before having to get of the time. A complete waste of my time. I cannot believe they can stay business with these shenanigans. I’ll avoid this company like the plague moving forward as the lack of accountability is disgraceful.

This was the best 2 flights I have had with American out of SGF. Great crew both flights.

It was a red eye flight, so no meals were provided, but it was fine with snacks. The seats felt cramped and almost too narrow.

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.

I liked the turn-style feature at gate 209B at LAX. Very efficient process. The gate staff also made several, clearly directed announcements so I felt very informed.

The crew was delayed because they came on another flight that was delayed due to weather 10pm flight left at 1.30 am The airline made no effort to align alternate crew

The seats were awful, hard plastic covered in sheet vinyl. The airline tries to scam you into paying extra to get seat together when the flight wasn’t full. They were going to separate a family with young children but my wife who had a row to herself gave up her seat so the young mom could be with her young boys. I’m never giving this airline my money again.

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

Information on your arrival and departure airports