$61 Find Cheap Flights from San Diego 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 Diego to Illinois departing on 12/25. 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 Diego to Illinois.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from San Diego to Illinois.
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Cheap Flights from San Diego to Illinois

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Chicago
Chicagononstop$157
Moline
Moline1 stop$314
Peoria
Peoria1 stop$177
St. Louis
St. Louis1 stop$124
Chicago
Chicagononstop$157
Moline
Moline1 stop$314
Peoria
Peoria1 stop$177
St. Louis
St. Louis1 stop$124

Book Cheap San Diego 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 Diego 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 Diego to Illinois

Tue, Dec 16 - Wed, Dec 17
Frontier Logo
6:34 am - 10:14 amSAN-STL
25h 40m1 stop
Frontier Logo
7:43 pm - 7:15 pmSTL-SAN
25h 32m1 stop
$124Frontier
Find Deal
Thu, Dec 11 - Mon, Dec 15
Frontier Logo
6:34 am - 10:14 amSAN-STL
25h 40m1 stop
Frontier Logo
7:43 pm - 11:59 pmSTL-SAN
6h 16m1 stop
$130Frontier
Find Deal
Tue, Mar 3 - Tue, Mar 10
Alaska Airlines Logo
5:00 pm - 11:10 pmSAN-ORD
4h 10mnonstop
Alaska Airlines Logo
9:00 am - 11:25 amORD-SAN
4h 25mnonstop
$157Alaska Airlines
Find Deal
Wed, Dec 3 - Sun, Dec 7
American Airlines Logo
1:25 pm - 7:46 pmSAN-ORD
4h 21mnonstop
American Airlines Logo
6:10 pm - 8:45 pmORD-SAN
4h 35mnonstop
$165American Airlines
Find Deal
Mon, Dec 22 - Sat, Jan 24
United Airlines Logo
10:30 pm - 4:38 amSAN-ORD
4h 08mnonstop
United Airlines Logo
7:10 am - 9:40 amORD-SAN
4h 30mnonstop
$167United Airlines
Find Deal
Wed, Nov 19 - Wed, Nov 26
Southwest Logo
5:00 pm - 10:55 pmSAN-MDW
3h 55mnonstop
Southwest Logo
5:15 am - 9:25 amMDW-SAN
6h 10m1 stop
$167Southwest
Find Deal
Thu, Nov 27 - Thu, Dec 4
American Airlines Logo
1:05 pm - 7:26 pmSAN-ORD
4h 21mnonstop
American Airlines Logo
6:10 pm - 8:45 pmORD-SAN
4h 35mnonstop
$170American Airlines
Find Deal
Sat, Dec 6 - Sat, Dec 13
Southwest Logo
9:10 am - 9:50 pmSAN-ORD
10h 40m1 stop
Southwest Logo
1:00 pm - 5:25 pmORD-SAN
6h 25m1 stop
$172Southwest
Find Deal
Sat, Nov 22 - Tue, Nov 25
United Airlines Logo
5:21 pm - 11:30 pmSAN-ORD
4h 09mnonstop
United Airlines Logo
7:10 am - 9:39 amORD-SAN
4h 29mnonstop
$173United Airlines
Find Deal
Mon, Mar 2 - Mon, Mar 9
Alaska Airlines Logo
8:05 am - 1:59 pmSAN-ORD
3h 54mnonstop
Alaska Airlines Logo
9:00 am - 11:25 amORD-SAN
4h 25mnonstop
$175Alaska Airlines
Find Deal
Booking Insights

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

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

What is the cheapest San Diego 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 Diego found in the last 72 hours was to Chicago, at $165 round-trip. The most popular route is from San Diego (SAN) to Chicago O'Hare Intl Airport (ORD), and the cheapest round-trip airline ticket found on this route in the last 72 hours was $165.

Can I save money by flying with a layover from San Diego 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 $285, prices are generally cheapest when you fly direct.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from San Diego 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 Diego to Illinois is September, when tickets cost $240 (return) on average. On the other hand, the most expensive months are March and December, when the average cost of round-trip tickets is $422 and $411 respectively.

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

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

When flying from San Diego to Illinois, you should consider leaving on a Thursday and avoid Sundays if you are looking for the best rates. For your return to San Diego, you’ll find the best rates on Fridays and the most expensive ones on Sundays.

How far in advance should I book a flight from San Diego 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 Diego 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 Diego to Illinois, you should book around 4 weeks before departure, which saves you about 34% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 19 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$61
Best time to beat the crowds with an average 13% drop in price.
Most popular time to fly with an average 17% increase in price.
Flight from San Diego to St. Louis

FAQs - booking Illinois flights

  • How does KAYAK find such low prices on flights from San Diego 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 Diego to Illinois.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from San Diego 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 Diego 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 Diego 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 Diego 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 Diego 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 in the evening, when round-trip flights cost $269 on average. Morning departures are around 80% more expensive than evening flights, on average. The most expensive time of day to fly to Illinois is generally in the morning, which is peak travel time and where the average cost of a ticket is $484.

Top tips for finding cheap flights to Illinois

  • Looking for a cheap flight? 25% of our users found tickets from San Diego to the following destinations at these prices or less: Chicago $139 one-way - $268 round-trip

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

 
See real verified KAYAK customer reviews for airlines flying from San Diego 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 Diego 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 11214 reviews
7.8Comfort
7.1Food
7.0Entertainment
8.1Boarding
8.5Crew
Airline reviews

Check in online didn't accept my confirmation number so i could only check in with assistance at the airport and ended up with s creepy middle seat.

4.0 OkayMarco, Oct 2025SAN - ORD
Read more Alaska Airlines reviews

Check in online didn't accept my confirmation number so i could only check in with assistance at the airport and ended up with s creepy middle seat.

It was the most expensive Alaska Airlines ticket I’ve ever purchased. I had a middle seat with no legroom or space compared to any other middle seat I’ve hadThere was a silver box under the seat that took up 70% of my legroom on the most narrow 737 max the crew flat out would not help they would not help with bags they would not help with garbage there was no coffee,It was definitely not one of my better experiences on Alaska.

Sitting on the ground for 2 hours waiting for a gate wasn't fun.

It was a great experience, friendly staff and good snacks

Very mediocre, and disappointing for the price of the ticket

My flight wait is 3 hours delayed due to Unknown reason. We waited a very long time in the tarmac. Our flight 24 was scheduled @ 7, therefore we left my house at 330 to park our car. We were at the gate @ 530, then we were told at 6a that it will be late , we boarded at 930 but did not take off until 1015. Therefore my arranged pick up in JFK was cancelled because of no show. Before all these I got an email offers of changing my flight to a different date which I took a day earlier. I will never again take Alaska Airlines, very Inefficient and Disappointing.

Such great crew, from checkin to the plane. So friendly and helpful, I was genuinely impressed.

Seats extremely uncomfortable, no entertainment, no snacks, and when boarding, half of the passengers needed to check in the carry on luggage without any explanation.

The flight was jumping between being delayed and closer to schedule about 5 times. Alaska air website showed incorrect times while google had latest info. This panic was horrible to deal with.

I always heard this was a terrible airline but I was happy to experience otherwise. The seats were more comfortable than delta. They did board late and gate was a little chaotic, which is to be expected for a budget airline. I would definitely do it again for that price.

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.

The cabin was quiet for the redeye flight. The area was clean. The staff was great. The 787 Max was in good condition. Drawbacks were that the seat widths were tight for some passengers. The seat padding was at best average and for a long flight uncomfortable.

Worst experience I had on Southwest. Still better than most, but the seating was barely tolerable.

It was okay. The plane was delayed from earlier in the day, but they kept updating the departure time, sometimes later, sometimes earlier. That was stressful. Once we finally got on and took off, it was fine. I was supposed to have a connection in Chicago to Los Angeles, and the time for so late I was rebooked to arrive in LA 3 hours late. The departure time to Chicago later became early enough to have taken my original connection and arrive earlier but that wasn't an option.

Delayed flight. Nicest crew member was a SW pilot flying seated next to me who kindly move to seat the final passenger. Flight extra delayed. My cup of refreshment of ginger ale was so packed with ice it was literally 2 sips.

No trays in our seats, we sat in first row, purchased a business class fare. Had to hold our drinks and snack in our hands. No plugs for our cell phones. Had to pay for it a drink cocktail each. Seats so uncomfortable.

Flight was delayed only slightly before takeoff due to traffic control. However, the flight arrived early to ORD. Good flight. United has been very reliable for me.

Another delayed flight. When the delays exceed the duration of the flight, it’s a problem.

After boarding the plane in Chicago, the passengers were told that there was a technical problem with the plane. Passengers remained on the plane as they tried to fix the problem. After what was probably an hour passengers were told that there was a need to change planes as the problem was not solved. Passengers disembarked and boarded another plane. After taxing to the runway and waiting for takeoff, passengers were told that owing to the thunderstorm the flight was unable to take off but would try and reroute. After some time passengers were told there wasn't enough fuel for the new route and the plane had to return to the gate for additional fuel. after another log delay the flight got underway. On the plane there was food, drinks, ice or entertainment. We were a glass of water, which appeared rationed. Flight arrived about 5 hours late. The pilot was fantastic and communicated with the passengers throughout the ordeal.

Better WiFi. I cannot understand that in 2025, United is so behind on a technology that is now a necessity and still painfully unreliable, slow and keeps disconnecting.

Trip was great. A wild landing in Ottawa with the wind and rain, but the pilot did a great job. Always love flying United.👍

Excellent experience. Starting with the agent at the Premier bag drop who noticed I was very early for my scheduled flight and offered to rebook me on an earlier flight with my seat preference. She would not let me leave the counter until she knew that all of the changes and new boarding pass showed up on my United app. At the gate, the flight boarded quickly such that we departed early and the flight was smooth. We arrived 20 minutes early at ORD and I was able to be home in time for dinner. One of the best flights I've had.

Salina to travers city was great! But the sept 24 Tranverse city was not! Traverse city to chichago was cancelled, i went to Denver & got to Salina 6 hours later!

See previous note about the passenger in Denver who threw my husband's bag out of the overhead bin in order to maker room for his own. And the flight attendant back up the new passenger.

I was in first class. The outlets at my seat did not work. The plane was shabby and run down. I had prepurchsed a day subscription for internet that was not redeemable. I had to repurchase the internet for my flight and then it didn’t work anyway. Quite disappointed in what was supposed to be the launch of a great vacation.

Flight attendant in first class gave poor service (like he didn't want to be there) and food was awful. We sat waiting for gate upon arrival over 45 mins.

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.

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.

Excellent - explanations were clear staff was nice and flight was comfortable

Lost bag and 2 days no word leaving for cruise no clothes or stuff

The entertainment package was vast and the selections were very current. Keep updating it was great.

The seat was so hard my tailbone was aching The crew was kind of a b**** because I made a joke that I didn't care if they close the door I total c*** when she was trying to f****** act like she was mad at me because I said that The flight was bumpy. Sure you didnt have control over that.

Any flight to ORD after about 2pm this summer has been challenging. Flight was delayed getting in (coming from ORD) and that led to it not leaving before a ground stop due to lightening before they could fuel the plane, and so forth. They made up some time but we were still late in arriving at ORD, and that led to missed connections.

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.

It was a short flight so no food or entertainment….

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