Cheap flights from Chicago to St. Louis from $46
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Chicago to St. Louis departing on 9/13. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
Discover deals from 900+ travel sites with momondo.
Save money when you book flights with momondo
Big names and deals
Big names and deals
Search 100s of travel sites to compare prices.Filter for what you want
Filter for what you want
Free Wi-Fi? Stopover? Instantly customize your results.Trusted and free
Trusted and free
We’re completely free to use - no hidden charges or fees.Price Alerts
Price Alerts
Not ready to book? to track prices.Find the cheapest flights from Chicago to St. Louis
Cheap round-trip flights
Cheap one-way flights
Cheap last minute flights
Cheap direct flights
American Airlines flights from Chicago to St. Louis
Our best American Airlines deals on Chicago to St. Louis flight tickets
Southern / Mokulele flights from Chicago to St. Louis
Our best Southern / Mokulele deals on Chicago to St. Louis flight tickets
See travel insights to St. Louis from
How to get the cheapest flight ticket from Chicago to St. Louis
Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip
What is the cheapest month to fly to St. Louis?
In general, September is the cheapest month to fly from Chicago to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $243. The month of April is another great option to travel to St. Louis, with average flight prices from Chicago averaging around $268.
What is the cheapest day to depart on your flight to St. Louis?
The cheapest day to depart on your flight to St. Louis is on a Thursday when prices can be found for as low as $314. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Monday because tickets tend to average around $510. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.
What is the cheapest time of day to depart on your flight to St. Louis?
Flying to St. Louis from Chicago in the evening is the least expensive time of day to depart. momondo users have found prices as low as $289 when looking at flights departing in the evening. In the morning is when there is more demand to fly to St. Louis, so prices are often more expensive at around $435 per ticket.
What is the cheapest Chicago to Lambert-St Louis flight route?
Fly from Chicago O'Hare Intl to Lambert-St Louis for the best Chicago - Lambert-St Louis flight prices
How far in advance should I book a flight to St. Louis?
You are more likely to see cheaper flights to St. Louis from Chicago when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $271 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Chicago for as low as $103 on momondo.
What cabin class options are available on Chicago to Lambert-St Louis flights?
There are 4 cabin classes available to choose from on Chicago to Lambert-St Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.
What is the cheapest airline that flies from Chicago to Lambert-St Louis?
Southwest, United Airlines, and Frontier are the most popular carriers operating from Chicago to Lambert-St Louis
What airlines fly to St. Louis?
American Airlines, United Airlines and Contour are the top three most popular airlines that fly to St. Louis from Chicago according to our data. American Airlines is the first choice among our users, with 45% of people opting to fly with this airline when traveling to St. Louis. Keep in mind that there are 5 different airlines that fly to St. Louis on a routine basis, so you have a few additional options to choose from.
How many flights depart from Chicago to St. Louis on average per day?
The number of flights available between Chicago and St. Louis is 41 per day as of July 2025. The most frequent departure time is 7:00PM, with 42% of daily flights leaving in the evening.
How many flights depart from Chicago to St. Louis on average per week?
As of July 2025, there are 293 flights per week flying from Chicago to St. Louis. The most common day of the week flights depart is Thu, with 26% of flights taking off on this day.
When to book flights from Chicago to St. Louis
Cheap Chicago to St. Louis (CHI to STL) flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from Chicago to St. Louis
Is flying the fastest way to get from Chicago to St. Louis?
The quickest way to travel this route is to take a flight from Chicago to St. Louis, doing so can potentially save up to 4h 25m of travel time. While these options may take longer, booking a train from Chicago to St. Louis or a bus from Chicago to St. Louis may suit your needs if travel time is less of a factor in your decision making.
Is flying the cheapest way to get from Chicago to St. Louis?
A train from Chicago to St. Louis is currently going to be the least expensive option currently available. You can also find deals for a flight from Chicago to St. Louis starting at $91, or consider a bus from Chicago to St. Louis starting at $87. Both of these alternative options are worth considering when looking to reach your destination.
How far is Chicago to Lambert-St Louis by plane?
There are 262.0 mi between Chicago and Lambert-St Louis. Typically, this will take 1h 10m by plane in normal conditions.
When did momondo last update prices for flights from Chicago to Lambert-St Louis Airport?
Prices for flights from Chicago to Lambert-St Louis Airport were last updated today.
How many operators does momondo search for flights from Chicago to Lambert-St Louis Airport?
As of July 2025, there are 4 operators available to choose from for flights from Chicago to Lambert-St Louis Airport.
How old do you have to be to fly from Chicago to Lambert-St Louis Airport?
The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Chicago to Lambert-St Louis Airport.
What documentation or ID do you need to fly to Lambert-St Louis Airport?
The travel and health documents required for your trip to Lambert-St Louis Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Lambert-St Louis Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.
What is the most popular plane model from Chicago to St. Louis?
momondo data reveals that the most frequently booked plane model on the route from Chicago to St. Louis is Airbus A319, representing 11.67% of all bookings. The subsequent popular models are Boeing 737 MAX 8 at 10.13%, Boeing 737-800 at 9.93%, and Embraer 175 at 8.99%.
What is the most popular airline from Chicago to St. Louis?
Based on momondo bookings for flights between Chicago and St. Louis, the leading airline is Southwest, making up 35% of the total bookings. Other popular airlines include United Airlines with 26%, American Airlines with 25%, and Southern / Mokulele with 14%.
Best airlines flying from Chicago to St. Louis
Compare and see reviews for airlines that fly from Chicago to St. Louis with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $116 | Free Cancellation | Rating 7.2 10,000 reviews | |||
| PriceFrom $116 | Free Cancellation | Rating 8.0 4,266 reviews | |||
| PriceFrom $118 | Free Cancellation | Rating 6.4 26 reviews | |||
| PriceFrom $152 | Free Cancellation | Rating 7.4 8,861 reviews |
Southwest Flights From Chicago to St. Louis
Southwest operates around 24 flights from Chicago to St. Louis every week. The average price of these flights found in the last 72 hours has been $328, but momondo users have found Southwest deals from Chicago to St. Louis from as low as $116 round-trip. Southwest has been scored 8.0/10 in 4,266 reviews.
United Airlines Flights From Chicago to St. Louis
Across 8,861 United Airlines reviews on momondo, the average score is 7.4/10. United Airlines flies from Chicago to St. Louis about 49 times each week, with ticket deals ranging from $152 to $319. Price data is based on momondo searches in the last 72 hours.
Traveling to a place near St. Louis?
Book flights to St. Louis if you plan to visit one of these locationsWhy use momondo?
Why should I use momondo to find a flight deal from Chicago to St. Louis?
To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to St. Louis from Chicago.
Can I find flights from Chicago to St. Louis with flexible booking policies on momondo?
Yes. momondo allows you to filter the results for Chicago to St. Louis flights to just show those with flexible booking policies.
How can momondo help me find flights from Chicago to St. Louis?
Once you have performed a search for Chicago to St. Louis flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.
I’m not ready to book a flight from Chicago to St. Louis right now. Can momondo alert me if prices change?
Price alerts on flights to St. Louis from Chicago are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.