Cheap flights from Chicago to San Antonio from $85

If you aren’t able to travel during the month of October, then book flights to San Antonio from Chicago during August instead. Flights to San Antonio in August, while not as cheap as those in October, still average around $347.

The cheapest day to depart on your flight to San Antonio is on a Tuesday when prices can be found for as low as $358. This is often the case because there is less demand to fly during this day of the week. Be sure to avoid booking your departure on a Sunday as prices are generally higher than usual. According to our data, the average ticket price to San Antonio on Sunday is $446.

According to our data, the cheapest time of day to fly to San Antonio is at noon. momondo users have found flights departing from Chicago to San Antonio at noon for as low as $386. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights to San Antonio are more costly in the afternoon, with an average ticket price of $397. Departure times in the afternoon fall within the peak daily travel times, which is why tickets can be more expensive.

Fly from Chicago O'Hare Intl to San Antonio for the best Chicago - San Antonio flight prices

You are more likely to see cheaper flights to San Antonio from Chicago when booking weeks ahead of your departure date. In general, you can expect to find flights to San Antonio for around $374 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to San Antonio from Chicago for as low as $322 on momondo.

There are 4 cabin classes available to choose from on Chicago to San Antonio flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

You could potentially save up to 31% on your flight if you consider stops on a Chicago to San Antonio flight.

As of February 2026, prices for Chicago to San Antonio flights are approximately 2% more expensive when compared to flights at the same time last year.

Spirit Airlines, Frontier, and United Airlines are the most popular carriers operating from Chicago to San Antonio

American Airlines, United Airlines and Frontier are the top three most popular airlines that fly to San Antonio from Chicago according to our data. American Airlines is the first choice among our users, with 38% of people opting to fly with this airline when traveling to San Antonio. Keep in mind that there are 5 different airlines that fly to San Antonio on a routine basis, so you have a few additional options to choose from.

Atlanta (ATL) was the most common stop: 86% of momondo users choosing 1-stop flights on this route connected there.

Flights via Atlanta (ATL) offer the lowest average round-trip price of $238.

Flights connecting via Atlanta (ATL) have the shortest average one-way travel time: 5h 19m.

Atlanta (ATL) has the shortest average layover time for this route: 0h 47m.

The number of flights available between Chicago and San Antonio is 17 per day as of February 2026. The most frequent departure time is 8:00PM, with 60% of daily flights leaving in the evening.

122 flights are operational weekly from Chicago to San Antonio as of February 2026. The most popular departure day for this route is Fri, with 20% of flights per week taking off on this day.