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$71+ Cheap flights from Illinois to San Antonio (SAT)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/10. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SAT
Oct 16 — Oct 231
Thu 10/16
Thu 10/23
1 adult, Economy
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Cheap flight deals from Illinois to San Antonio

Keep the following information in mind while searching for Illinois to San Antonio flight deals. Data was last updated September 16, 2025.

Round-trip from

$151
(United Airlines)

One-way from

$71
(United Airlines)

Popular in

March

Cheapest in

October

Average price

$406

Good round-trip deal

$295 or less

Good one-way deal

$153 or less
From Illinois to San Antonio
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One-way flight from Illinois to San Antonio
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Highest demand for flights based on searches. 6% potential increase in price ($26 potential increase over avg. RT price).
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Cheapest flight prices on average. 0% potential price decrease ($4 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Price to beat on a round-trip flight from Illinois to San Antonio.
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Price to beat on a one-way flight from Illinois to San Antonio.
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Find flight deals from Illinois to San Antonio

Cheapest flights from Illinois to San Antonio
Explore the most affordable flight options available from Illinois to San Antonio. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 16, 2025.

This United Airlines deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/111:35 pmSTL - SAT
1 stop8h 14mUnited Airlines
Mon 11/174:24 pmSAT - STL
1 stop5h 58mUnited Airlines
Deal found 9/15$151
This Frontier deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/166:50 amORD - SAT
1 stop12h 51mFrontier
Sat 10/185:32 pmSAT - ORD
1 stop6h 21mFrontier
Deal found 9/15$158
This Cheapflightsfares deal was found by Cheapflights users on 9/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/17:15 amORD - SAT
1 stop7h 02mFrontier
Mon 11/35:35 pmSAT - ORD
1 stop6h 36mFrontier
Deal found 9/16$159
This American Airlines deal was found by Cheapflights users on 9/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/145:56 pmSTL - SAT
1 stop6h 32mAmerican Airlines
Tue 11/186:00 amSAT - STL
1 stop6h 37mAmerican Airlines
Deal found 9/14$159
This Frontier deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/125:05 amORD - SAT
1 stop11h 47mFrontier
Sat 10/185:32 pmSAT - ORD
1 stop6h 21mFrontier
Deal found 9/15$160
This Priceline deal was found by Cheapflights users on 9/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/266:20 amMDW - SAT
1 stop10h 10mFrontier
Mon 9/295:40 pmSAT - MDW
1 stop5h 40mFrontier
Deal found 9/16$160
This Booking.com deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/255:10 amORD - SAT
1 stop5h 38mFrontier
Fri 9/267:25 pmSAT - ORD
1 stop26h 03mFrontier
Deal found 9/15$162
This Booking.com deal was found by Cheapflights users on 9/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/17:55 pmSTL - SAT
1 stop23h 20mFrontier
Sun 10/58:20 pmSAT - STL
1 stop12h 46mFrontier
Deal found 9/16$164
This Priceline deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/278:25 amORD - SAT
1 stop6h 02mFrontier
Fri 10/35:40 pmSAT - ORD
1 stop5h 59mFrontier
Deal found 9/15$166
This Frontier deal was found by Cheapflights users on 9/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/237:52 pmSTL - SAT
1 stop23h 49mFrontier
Mon 10/2710:54 amSAT - STL
1 stop8h 32mFrontier
Deal found 9/16$166
This Booking.com deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/278:25 amORD - SAT
1 stop6h 02mFrontier
Thu 10/211:33 amSAT - ORD
1 stop12h 06mFrontier
Deal found 9/15$167
This Priceline deal was found by Cheapflights users on 9/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/176:20 amMDW - SAT
1 stop10h 30mFrontier
Sun 10/195:47 pmSAT - MDW
1 stop5h 59mFrontier
Deal found 9/16$167

Cheapflights Fare Finder

 
Customize your flight search to find flights from Illinois to San Antonio that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated September 16, 2025.
Use the filters below to find and compare flights from Illinois to San Antonio that are best for you.

Fly from

Illinois

Fly to

San Antonio

Route

Depart

Return

Price

St. LouisSan Antonio

STL - SAT

STLSAT

Lambert-St Louis

Fri 10/10

7:52 pm-4:37 pm

1 stop20h 45m

San Antonio

Mon 10/13

8:20 pm-9:07 am

1 stop12h 47m

$164

St. LouisSan Antonio

STL - SAT

STLSAT

Lambert-St Louis

Mon 12/8

6:00 am-12:10 pm

1 stop6h 10m

San Antonio

Mon 12/8

4:51 pm-11:41 pm

1 stop6h 50m

$197

St. LouisSan Antonio

STL - SAT

STLSAT

Lambert-St Louis

Thu 10/2

7:55 pm-11:46 am

1 stop15h 51m

San Antonio

Sun 10/5

9:55 am-9:06 am

1 stop23h 11m

$201

St. LouisSan Antonio

STL - SAT

STLSAT

Lambert-St Louis

Fri 1/16

10:07 am-3:31 pm

1 stop5h 24m

San Antonio

Mon 1/19

4:04 pm-10:00 pm

1 stop5h 56m

$202

St. LouisSan Antonio

STL - SAT

STLSAT

Lambert-St Louis

Thu 10/16

6:15 am-1:15 pm

1 stop7h 00m

San Antonio

Tue 10/21

4:39 pm-11:58 pm

1 stop7h 19m

$213

St. LouisSan Antonio

STL - SAT

STLSAT

Lambert-St Louis

Thu 11/13

9:00 am-4:58 pm

1 stop7h 58m

San Antonio

Sun 11/16

5:30 am-10:39 am

1 stop5h 09m

$221

St. LouisSan Antonio

STL - SAT

STLSAT

Lambert-St Louis

Fri 11/14

9:00 am-4:58 pm

1 stop7h 58m

San Antonio

Tue 11/18

5:30 am-3:47 pm

2 stops10h 17m

$226

ChicagoSan Antonio

MDW - SAT

MDWSAT

Chicago Midway

Thu 12/4

2:15 pm-10:27 pm

1 stop8h 12m

San Antonio

Mon 12/8

6:42 pm-9:32 pm

1 stop26h 50m

$227

ChicagoSan Antonio

MDW - SAT

MDWSAT

Chicago Midway

Sun 11/9

12:30 pm-7:30 pm

1 stop7h 00m

San Antonio

Mon 11/10

8:25 pm-11:38 am

2 stops15h 13m

$252

ChicagoSan Antonio

MDW - SAT

MDWSAT

Chicago Midway

Fri 9/26

6:20 am-4:30 pm

1 stop10h 10m

San Antonio

Sun 9/28

8:20 pm-3:53 pm

1 stop19h 33m

$258

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/14

Showing 1-10 of 60 results
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Best time to book a flight from Illinois to San Antonio

Have a flexible travel schedule? Discover the best time to fly to San Antonio from Illinois with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Illinois to San Antonio

What is the cheapest month to book a flight from Illinois to San Antonio?

Currently, August is the cheapest month in which you can book a flight from Illinois to San Antonio (average of $295). Flying from Illinois to San Antonio in March is currently the most expensive (average of $376). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from IL to SAT?

Find hourly flight availability from Illinois to San Antonio. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 16, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Illinois to San Antonio as you normally would.

Weekly flight availability from Illinois to San Antonio

Explore weekly flight availability from Illinois to San Antonio. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated September 16, 2025.

The most flights from USIL to SAT are scheduled on a Monday (26 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (8 on average).

Related info for your journey

Find useful and relevant information for your journey from Illinois to San Antonio. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to San Antonio from Illinois?

    Most people fly into San Antonio (SAT) if they book a flight to San Antonio from Illinois. San Antonio is conveniently located just 7.6 mi from San Antonio’s city center.

  • How long is the flight from Illinois to San Antonio?

    Frontier, Delta, and United Airlines can get you from Illinois to San Antonio in just under 5h 24m. Your travel time can differ by up to 15h 21m. The distance between Illinois and San Antonio is about 786 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

  • What are the cheapest airlines to fly from Illinois to San Antonio one-way?

    For one-way options, check prices for United Airlines. According to our data, you can fly for as low as $71. Users have also found prices from $80 and $112 on Frontier and Spirit Airlines, respectively.

  • What are the most popular routes from Illinois to San Antonio?

    Most travelers choose Chicago O'Hare Intl - San Antonio, Chicago Midway - San Antonio or Lambert-St Louis - San Antonio when deciding on the best route from Illinois to San Antonio.

  • What are the most reliable airlines from Illinois to San Antonio?

    Before booking your flight to San Antonio from Illinois, check out the most reliable airlines to get you to your destination on time: SkyWest Airlines (96%), Republic Airways (85%), Air Canada( 81%).

  • What are the cheapest flights from Illinois to San Antonio?

    While on average a flight from Illinois to San Antonio is generally $703, our data shows the cheapest flight currently is $143. When looking at the most popular route, (Chicago O'Hare Intl - San Antonio), you can expect to pay $179 for that flight.

  • Can I find deals for flights from Illinois to San Antonio that include hotel bookings?

    Yes. In addition to deals on Illinois to San Antonio flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Illinois to San Antonio?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Illinois to San Antonio.

  • Can I find deals for business class flights from Illinois to San Antonio?

    Yes. Cheapflights offers flight deals from Illinois to San Antonio by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Illinois to San Antonio?

    Currently, August is the cheapest month in which you can book a flight from Illinois to San Antonio (average of $295). Flying from Illinois to San Antonio in March is currently the most expensive (average of $376). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near San Antonio?

Book flights to San Antonio if you plan to visit one of these locations
New Braunfels
Kerrville

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Alternative routes for Illinois to San Antonio

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Top 6 airlines flying from Illinois to San Antonio

Discover the top 6 airlines that operate flights from Illinois to San Antonio. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated September 16, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$125Average$217FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$172Average$288FlexibilityNo cancel feeOn-time65%
American AirlinesCheapest$194Average$398FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$203Average$501FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$258Average$433FlexibilityNo cancel feeOn-time69%
DeltaCheapest$258Average$348FlexibilityNo cancel feeOn-timeN/A

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