$74 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 4/7. 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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Flight Deals

Cheap Flights from San Diego to Illinois

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Chicago
Chicago1 stop$174
Moline
Moline1 stop$320
Peoria
Peoria1 stop$374
Bloomington
Bloomington1 stop$349
St. Louis
St. Louis1 stop$158
Chicago
Chicago1 stop$174
Moline
Moline1 stop$320
Peoria
Peoria1 stop$374
Bloomington
Bloomington1 stop$349
St. Louis
St. Louis1 stop$158

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

Fri, Apr 17 - Mon, Apr 20
Frontier Logo
12:25 pm - 7:32 pm
SAN
-
STL
29h 07m
1 stop
Frontier Logo
8:17 pm - 11:06 pm
STL
-
SAN
28h 49m
1 stop
$158Frontier
Thu, Apr 9 - Mon, Apr 13
Frontier Logo
6:25 am - 9:48 am
SAN
-
STL
25h 23m
1 stop
Frontier Logo
8:19 pm - 8:04 pm
STL
-
SAN
25h 45m
1 stop
$171Frontier
Thu, Apr 16 - Mon, Apr 20
Frontier Logo
7:23 pm - 5:00 pm
SAN
-
ORD
19h 37m
1 stop
Frontier Logo
7:35 am - 5:48 pm
ORD
-
SAN
12h 13m
1 stop
$174Frontier
Sat, Apr 11 - Sat, Apr 18
Hawaiian Airlines Logo
12:37 pm - 7:02 pm
SAN
-
ORD
4h 25mnonstop
Hawaiian Airlines Logo
4:10 pm - 6:55 pm
ORD
-
SAN
4h 45mnonstop
$186Hawaiian Airlines
Sat, Apr 18 - Sat, Apr 25
Southwest Logo
10:40 pm - 4:35 am
SAN
-
MDW
3h 55mnonstop
Southwest Logo
6:15 am - 8:30 am
MDW
-
SAN
4h 15mnonstop
$197Southwest
Wed, Apr 29 - Wed, May 6
Southwest Logo
10:40 pm - 4:35 am
SAN
-
MDW
3h 55mnonstop
Southwest Logo
7:30 am - 11:20 am
MDW
-
SAN
5h 50m
1 stop
$203Southwest
Thu, May 7 - Tue, May 12
American Airlines Logo
3:21 pm - 11:26 pm
SAN
-
MLI
6h 05m
1 stop
American Airlines Logo
3:48 pm - 8:33 pm
MLI
-
SAN
6h 45m
1 stop
$320American Airlines
Thu, May 7 - Tue, May 12
American Airlines Logo
12:17 pm - 11:26 pm
SAN
-
MLI
9h 09m
1 stop
American Airlines Logo
12:04 pm - 6:28 pm
MLI
-
SAN
8h 24m
2 stops
$325American Airlines
Tue, May 19 - Wed, May 27
United Airlines Logo
10:55 am - 10:29 pm
SAN
-
BMI
9h 34m
2 stops
United Airlines Logo
9:44 am - 5:41 pm
BMI
-
SAN
9h 57m
2 stops
$379United Airlines
Tue, Apr 21 - Sat, Apr 25
United Airlines Logo
11:00 am - 9:32 pm
SAN
-
MLI
8h 32m
1 stop
United Airlines Logo
1:55 pm - 6:53 pm
MLI
-
SAN
6h 58m
1 stop
$381United 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.

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 $177 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 $204.

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 $260 on average. Morning departures are around 67% 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 $433.

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 $315, 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 $232 (return) on average. On the other hand, the most expensive months are April and May, when the average cost of round-trip tickets is $353 and $341 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 Mondays.

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 3 weeks before departure, which saves you about 39% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 7 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$74
Best time to beat the crowds but there is an average 9% increase in price.
Most popular time to fly with an average 13% 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.

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 $174 one-way - $302 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 4321 reviews
8.1Boarding
8.0Comfort
8.6Crew
7.0Food
7.5Entertainment
Airline reviews

The problem with the seat assignments is that there were a lot of rows in the front that were empty but my row at the back was full. Just not so pleasant.

8.0 ExcellentTobin, Mar 2026
SJC - BUR
Read more Southwest reviews

The problem with the seat assignments is that there were a lot of rows in the front that were empty but my row at the back was full. Just not so pleasant.

Good but I prefer choose your own seat. With the new assigned seats they should board from the back I see no advantage to this new boarding. Just like every other airline

WiFi was not working and didn’t have a beverage service

Flight boarded late after announcing on time boarding. Flight arrived only a little late despite late departure. Had trouble connecting to WiFi

The Southwest experience has definitely taken a dive from its early days. You can no longer deferentiate from other airlines. Air travel is too expensive. Southwest is no longer budget friendly. They have lost me as a loyal customer.

The charges were ridiculous for an hour flight and the turbulence was very scary.

The seats are now more narrow. I paid for front row the seats in the front are even more narrow than before.

The wifi on the plane is great. The only issue that I have is that I prefer an aisle seat and on my trips this week, I was either in the middle or window. If we can work to secure aisle seating, I will be thrilled. Nice trip.

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

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

This was my first trip with Alaska Airlines (round trip DCA to San Diego). Despite a slight delay on the return flight, I feel compelled to post a RAVE review! I cannot praise the airline and the crew enough! Everyone was kind, professional, and courteous, every step of the way- excellent service, snacks, and entertainment! On both legs of the trip I inquired whether there were any free seating upgrades and my request were granted BOTH times! I’ve flown on other airlines where they won’t do that, even when those premium seats are empty. As a customer service professional myself, I can say I left my experience feeling like a valued customer and not just a number. I NEVER expected to praise an airline lol I’ll definitely go out of my way to fly with Alaska on future trips. Thank you for such an awesome experience!

I bought tickets MONTHS ago for a flight that left SAN at 14:30. That is what it says on our tickets. I was never notified of any time changes. During online check-in. I discovered the flight time had been changed to 15:45. This was unacceptable and had I been notified, I would have changed flights, or airlines. That departure time was unworkable with our plans. We called Alaska and asked for an explanation. They said flight time was changed 11/08/25. No proof of notification could be offered. We asked to be moved to an earlier flight. After much pleading, the rep said she would allow a “one time exception..” While I appreciate being moved, this was YOUR fault Alaska Airlines.

The room for legs is adequate for a 6’ tall man and the flight was comfortable. The cabin is clean and the crew is very friendly and pleasant.

Worst first/business class I have ever flown after 75 years on planes. Barely acceptable seats, terrible food, uninterested attendants, unavailable WiFi. I’ll never fly this airline again.

Again, very smooth and all of the Alaska folks were great. They continue to meet all my needs.

The whole experience went smoothly with no hitches along the way.

My Alaska Airlines return flight, although worked out in the end, didn't start off well. The initial plane that my family and I boarded was grounded because of a mishap that happened to one of the engines and everyone on board had to disembark the plane. Thankfully we were accommodated with a another plane but our initial flight was supposed to have departed at 11 pm San Diego time for Orlando but instead we ended up leaving at 1:40 am San Diego time. All Passengers were informed that part of the delay was that the plane had to be inspected by the captain, the food had to be stocked and the individuals responsible for fueling the plane left for the evening and had to be summoned to return to fill up our. The Alaska Airlines crew at the airport and on the plane were awesome and apologetic. I know that the crew wasn't responsible for the mishap of the engine but I think in the future the airline should offer a complimentary drink or (1) item of food other than pretzels, nuts or chips to all passengers since we're not to blame for the extreme set backs. The airline in general is good and I recommend to all flyers.

Complimentary light meal would be appreciated. But great flight crew service on all legs

Wonderful. Quick boarding. Early departure and we arrived 30 minutes early at our destination. Unfortunately, when you arrive early, there is still a departing aircraft at our gate. We had to park for 30 minutes until the gate was clear. So our early arrival was not really early at the gate. Otherwise it was a quick and smooth flight. Appreciated the efficiency.

Crew was great (professional, attentive, prompt). Snacks for 4 hrs flight is deplorable.

United Airlines is my preferred airlines and I am thankful for Gary who also help support me on the phone to switch my flight literally last min.

Seated dude next to me even though lots of empty rows. But main thing was we sat on the tarmac after landing for 30 minutes because of, in the words of the dude who sat next to me, “operational incompetence”. We got changing directions about where to pick up gate checked bags. Pilot and flight attendant were awesome though.

The food was terrible this time. Otherwise pleasant, quiet, on-time.

It was a pretty standard flight... until the almost hour and a half spent on the taxi way. I get that the weather has been poor but the delay had nothing to do with the weather and more to do with a plane with several issues tying up the gate. I get that that happens from time to time but this has been EVERY flight I've been on for the past 5 years and I fly 3 to 5 times a year. This isn't just United... it's American, it's Delta. It's an issue with the entire industry. I work for UPS and packages on a cargo plane get better service than people do these days. Anymore I HATE flying.

Perfect flight. Smooth flight. Arrived 20 minutes early at destination. Excellent service.

The flights were on time which was great give. It was holiday travel season and there’d been some weather issues. The only complaint and this is every time with United is the terrible seat design. The head rest is not built for comfort and having my neck bent forward for a cross country trip reminded me while I try not to take United flights as a rule.

Everything was absolutely wonderful from check in to baggage claim. Staff was very professional and sweet. Will definitely recommend United to family and friends.

There was no inflight service. Once we landed we were delayed to find a gate for an hour and a half which was 1/2 the total time in the air.

The chicken wrap was tiny ($13 for what looked like a 1/3 of a normal wrap?) and disgusting.

It was good experience this time. The flight was on time.

There was a delay with the plan which cause the flight to leave later and once arrived in Chicago there was another delay and some passengers missed their connecting flights

The gate agent had a really bad attitude and refused to help me get on the standby list. She just handed me a card and said I needed to call a number. I asked her to help with the AA app on my phone and she just shrugged and said she didnt know. After a few phone calls, I eventually just went to a different gate agent on the other side of the terminal and got the help I needed.

Overall, my last three trips on American Airlines have all been either delayed or "rescheduled" due to mechanical issues. At least on delay caused me to miss two possible connecting flights each later than the first. My last option for my last connection required the assistance of the onsite service desk (O'Hare Airport). The wait time for the service desk was such that it jeopardized getting booked on the last connecting flight available for the night. Suffice it to say, my latest experiences with American Airlines have caused me extensive loss of productive business and personal time and can therefore be classified as significantly less than satisfactory.

Waiting for gate in RDU for more than 20mins is crazy.

American Airlines was great and worked very hard to change my ticket so I could get an earlier, direct flight back to Dallas. However, I was informed that Kayak made mistakes with my itinerary and classified my ticket as desiring to be on the earlier flight instead of taking the necessary step of calling AA to get me on the standby list. This ended up keeping me from being added to the standby list and delayed me getting home by 6 hours. I am happy to discuss this further with Kayak so they can correct their procedures so this won't happen again.

Waited for oxygen tanks for 30 minutes after boarding was complete.

We flew in first class. The crew did not offer drinks before the flight took off, but they treated us well during the flight. The food was excellent. There was actually too much food served, but it was nice to have all the options.

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.

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

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

Information on your arrival and departure airports