$65 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 5/27. 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
Chicago2 stops$232
Moline
Moline1 stop$286
Peoria
Peoria1 stop$333
Bloomington
Bloomington1 stop$417
St. Louis
St. Louis1 stop$185
Chicago
Chicago2 stops$232
Moline
Moline1 stop$286
Peoria
Peoria1 stop$333
Bloomington
Bloomington1 stop$417
St. Louis
St. Louis1 stop$185

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

Sat, May 23 - Wed, May 27
Frontier Logo
9:37 am - 7:23 pm
SAN
-
STL
7h 46m
1 stop
Frontier Logo
8:08 pm - 11:50 pm
STL
-
SAN
5h 42m
1 stop
$185Frontier
Sun, May 24 - Sun, May 31
Frontier Logo
9:37 am - 7:23 pm
SAN
-
STL
7h 46m
1 stop
Frontier Logo
9:06 pm - 6:41 pm
STL
-
SAN
23h 35m
1 stop
$197Frontier
Sat, May 23 - Wed, May 27
Frontier Logo
6:25 am - 7:23 pm
SAN
-
STL
10h 58m
1 stop
Frontier Logo
8:08 pm - 11:50 pm
STL
-
SAN
5h 42m
1 stop
$205Frontier
Wed, May 27 - Wed, Jun 3
Alaska Airlines Logo
7:00 am - 1:14 pm
SAN
-
ORD
4h 14mnonstop
Alaska Airlines Logo
9:00 am - 11:37 am
ORD
-
SAN
4h 37mnonstop
$233Alaska Airlines
Sat, May 23 - Wed, Jun 3
United Airlines Logo
6:40 am - 1:09 pm
SAN
-
ORD
4h 29mnonstop
United Airlines Logo
4:05 pm - 6:30 pm
ORD
-
SAN
4h 25mnonstop
$237United Airlines
Sat, May 16 - Sat, May 23
Southwest Logo
6:20 am - 12:20 pm
SAN
-
MDW
4h 00mnonstop
Southwest Logo
6:15 am - 8:30 am
MDW
-
SAN
4h 15mnonstop
$237Southwest
Sat, May 16 - Sat, May 23
American Airlines Logo
6:15 am - 12:33 pm
SAN
-
ORD
4h 18mnonstop
American Airlines Logo
6:45 am - 9:04 am
ORD
-
SAN
4h 19mnonstop
$238American Airlines
Sat, May 16 - Sat, May 23
Southwest Logo
6:45 am - 2:25 pm
SAN
-
MDW
5h 40m
1 stop
Southwest Logo
6:15 am - 8:30 am
MDW
-
SAN
4h 15mnonstop
$247Southwest
Wed, Oct 21 - Wed, Oct 28
United Airlines Logo
2:09 pm - 12:14 am
SAN
-
MLI
8h 05m
1 stop
United Airlines Logo
3:52 pm - 9:57 pm
MLI
-
SAN
8h 05m
1 stop
$313United Airlines
Wed, Sep 23 - Sat, Sep 26
American Airlines Logo
3:04 pm - 11:03 pm
SAN
-
MLI
5h 59m
1 stop
American Airlines Logo
11:55 am - 8:02 pm
MLI
-
SAN
10h 07m
2 stops
$365American Airlines
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.

How much is a round-trip flight from San Diego to Illinois?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from San Diego to Illinois departing in May.

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 $237 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 $257.

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

The average price for all round-trip flights from San Diego to Illinois depending on the time of departure, clicked by users on KAYAK in the last 2 weeks.

The cheapest time of day to fly to Illinois is generally in the evening, when round-trip flights cost $264 on average. Morning departures are around 58% 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 $423.

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 $355, 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 February, when tickets cost $91 (return) on average. On the other hand, the most expensive months are December and May, when the average cost of round-trip tickets is $558 and $519 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 Friday and avoid Sundays if you are looking for the best rates. For your return to San Diego, you’ll find the best rates on Saturdays 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 47% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 9 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$65
Best time to beat the crowds but there is an average 11% increase in price.
Most popular time to fly with an average 15% increase in price.
Flight from San Diego to St. Louis

Flights from San Diego to Illinois: the best tips from KAYAK users

Insights shared by verified travelers who flew the route from San Diego to Illinois 
CupcakeFlew with Alaska Airlines
SAN
-
ORD
Apr 2026
Please bring a water bottle for hydration during the flight.
RodFlew with United Airlines
SAN
-
ORD
Sep 2024
Yes! Don’t reserve a flight with less than 1 1/2 hour connection time or you have a good possibility of missing your connection.

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.

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 $217 one-way - $347 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
SouthwestOverall score based on 4314 reviews
8.6Crew
7.0Food
8.0Comfort
7.5Entertainment
8.1Boarding
Airline reviews

The entire experience from boarding to landing was amazing! The crew were very friendly. Will definitely be back.

10.0 Excellentlarry, Apr 2026
LGB - PHX
Read more Southwest reviews

The entire experience from boarding to landing was amazing! The crew were very friendly. Will definitely be back.

no service at all due to turbulence. they should've at least given us snacks, there were only 10 people on the entire flight.

Delayed flight, lack of information, boarding process is a mess as is the carryon luggage causing issues when leaving the plane….just a poor experience.

Comfortable. Easy. No problems. Just wish they had gf options for snacks.

The crew was very kind and made going to Hawaii relaxing and fun to look forward to! Thank you Southwest for a pleasant flight!

For the first time in a long time, the Wi-Fi actually worked the entire flight! The flight crew was amazing as usual.

Great flight. I didn't get a drink because I was asleep whole on the flight.

Terrible. Even though there’s assigned seating now, they are still the slowest boarding airline of anyone.

It was good from LAX to Phoenix, But the connection in Phoenix to Tulsa was not that great. The staff on both flights were great. The choice of free entertainment was ok nothing to brag about. The 45 min delay because of some electrical issue wasn't great from Phoenix to Tulsa. We sat there with hardly any air, The seat I had was between windows so the side of the plane pushed in on you. My being a bigger man it then made the seating area uncomfortable. The seats on the plane had no power to connect to recharge your phone or anything. I would recommend that they should look into a slot or clamp to hold your phone to enjoy while watching the entertainment choices hands-free. Also make it possible to raise the inner seat by the window be able to raise the arm rest up to make more room for larger people to set more comfortably. I would also say other then that stop price gouging the airfare or nickel and diming everything. Not fair for people having to fly for emergencies and be paying for higher prices due to the season or holidays. Your making your money either way and the cost of flying is still going to be the same regardless if there's 100 people or 200 people.

Love them will get a Southwest card to track my points and keep flying with them. My family and I were pleased with the services.

More efficient with checking lines and boarding/checking bags when needed.

They were really helpful with every question and my kids had never been on a plane and the staff made them feel comfortable

I was on flight #3022 departed from San Diego, California to Medford, Oregon. I had Denise & Damaris as my flight attendants. I didn’t have much interaction with Damaris, but I did with Denise who had, this calm, cool collective voice when she spoke about the emergency exit plans before takeoff. I travel often and I’ve never met a flight attendant that can put you at ease. I felt she respects and takes pride in her position and more airlines need to adopt the integrity and respect that she has for Alaska Airlines. Debbie

All airlines should board planes back to front, instead of catering to higher priced tickets. The boarding groups are inefficient and delay takeoff time

Luggage was severely damaged. Flight was late for several hours

The ticketing counter in SD was a mess. The lady handling the First-Class check-in seemed overwhelmed until a supervisor replaced her. It took almost 20 minutes to get once couple checked in, and then she started walking around the counters while 7 people just stood in line. Once her supervisor arrived, she announced she was going on break, never to engage with customers again.

No outlets, plugs, way to charge the phone or service and no food on one leg o the trip, but other than that, great. Loved WIFI, the flight, the crew, the pilots, the schedule, etc. Great job. My new favorite airline!

I had a problem with my reservation and no one could help me understand what happened. I booked my flight months ago and received a confirmation email. In the confirmation email, it said that the flight would depart at 3:15 p.m. A few hours before the flight, I tried to go online and check in, and suddenly it said that the flight was leaving an hour earlier. I had to rush to get to the airport and almost didn't make it. No one could help me understand why this happened, and I'm really concerned that it might happen in the future. I would appreciate some support in this matter.

It was a super old plane so the first class experience was just not luxurious

Good as usual. Just wished my seat was assigned at online check in. Thanks anyways

Standard flight with a drinks and a snack- overall very quick flight. The flight attendants were very strict, bordered on rude.

Delayed - weather wasn't bad at either end. Also sat on tarmac in ORD.

boarded early to only find out that flight would sit at gate for 45 min to an hour. Landed in chicago and sat on runway for over an hour before got to gate. Total delay was extensive for a 45 min flight door to door.

The flight was significantly delayed. The inbound flight from EWR was delayed departing because of mechanical problems. My original departure from CLT was 5:28 pm but due to the delay of the inbound flight, after arrival, deplaning, cleaning, boarding, we did not push back from the gate until 9:00 pm. Once in the air, the flight was smooth and what was originally supposed to be an arrival in ORD at 7:30 pm local time turned out to be 9:35 pm.

The flight I was supposed to be on was supposed to take off at 1:50 from State College. It was delayed over and over and over again until somehow I had to rebook on a flight that was supposed to have left State College at 8 am that morning but didn't end up taking off until almost 6 pm. Not only was this completely unacceptable, the "token from United" was a 15 dollar meal voucher that has to be used by today. I would personally like some miles added to my account for this inconvenience. I was in transit for 8 hours from the time I arrive at State College Aiport to when I got home. I was supposed to be home at 3 pm and I returned at 8 pm. Unacceptable. I have not been on an on Time united flight in nearly 5 years.

newer aircraft, ability to connect my headset via blue tooth for entertainment.

Very comfortable flight, snacks and drinks were good, good communication from crew. Could have used a little more information on timing of boarding for group 5

Great flight. Got to watch a movie. Smooth flight and early arrival at ORD.

It was better than excellent. The staff in Mason City were great. The young woman that pushed my wheelchair did more than could be expected of her. She came from India 17 years ago. I don't remember her name.

After arriving in Chicago, we were taxiing for 1.5 hours with infrequent and untruthful updates about the amount of time it would take to arrive at the gate. Minimally, the team could have provided timing expectations that were more truthful, especially one their original expectations were not met.

It was good, the staff was great, and the food, was as usual, tea and biscuit. Bathroom was clean, and the plane was clean as well.

Very good I can’t complain one bit. Thank you American Airlines for making my flight enjoyable and safe!

The staff and service on American Airlines were truly outstanding. I had requested wheelchair assistance for my mother due to her knee issues, and the team went above and beyond every step of the way—from boarding in Boston to our arrival in Chicago. Their care, professionalism, and attentiveness made the entire experience smooth and stress-free. I’m very grateful for the support they provided.

Was not able to do a online check-in because the American Airlines system doesn't store our visa or other passport information, allowing us to have a trouble-free check-in. We were forced to have to check-in at the counter which Changes are upgrade status given that we were not able to check in much earlier.

The new planes (American Eagle) are beautiful and especially comfortable. The flight attendants are consistently professional and courteous. And, while it may seem inconsequential, the new liquid tube of coffee creamer—in contrast to the powdered coffee creamer—makes all the difference in a cup of coffee.

Boarding was quick and efficient. We arrived at our destination early.

I'm not sure American is capable of on-time arrivals and departures. When you land at ORD, you almost always get held on the tarmac because your gate is still occupied. I may have missed my connection, but that ended up up being significantly delayed as well. Once again, I finally got home well after midnight.

Crew at the gate was very crabby and not at all polite. The plane was very hot the entire flight. And the seat cushion was very worn out.

The staff are very, very professional. It's what flying should feel like.

Flight was delayed half hour before boarding, but when I checked flight aware the plane that would Pick us up had a delay of more than an hour. AA should let us know in advance to avoid waiting several hours in the airport

They didn’t offer a water, even after I asked

Remind customers of the need to have passport or new ID for boarding.

The flight never took off and we spent 7 hours at the airport

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.

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

Information on your arrival and departure airports