$145 Cheap Flights from St. Louis (STL) to Tri-Cities (TRI)

View $145 flight on Thu, Aug 21, 2025Opens in a new window

Popular airlines from St. Louis Lambert Intl. Airport (STL) to Tri-Cities, TN (TRI-Tri-Cities Regional)

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Cheap Flights from St. Louis to Tri-Cities (STL-TRI)

Prices were available within the past 7 days and start at $145 for one-way flights and $287 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Wed, Dec 24 - Wed, Dec 31
STL
St. Louis
TRI
Tri-Cities
$287 Roundtrip, found 17 hours ago
$287
Roundtrip
found 17 hours ago
Select Delta flight, departing Wed, Dec 24 from St. Louis to Tri-Cities, returning Wed, Dec 31, priced at $287 found 17 hours ago
Delta
Tue, Aug 26 - Wed, Sep 3
STL
St. Louis
TRI
Tri-Cities
$288 Roundtrip, found 12 hours ago
$288
Roundtrip
found 12 hours ago
Select Delta flight, departing Tue, Aug 26 from St. Louis to Tri-Cities, returning Wed, Sep 3, priced at $288 found 12 hours ago
Delta
Tue, Aug 26 - Sat, Aug 30
STL
St. Louis
TRI
Tri-Cities
$289 Roundtrip, found 12 hours ago
$289
Roundtrip
found 12 hours ago
Select Delta flight, departing Tue, Aug 26 from St. Louis to Tri-Cities, returning Sat, Aug 30, priced at $289 found 12 hours ago
Delta
Sat, Sep 20 - Sun, Sep 21
STL
St. Louis
TRI
Tri-Cities
$291 Roundtrip, found 2 days ago
$291
Roundtrip
found 2 days ago
Select Delta flight, departing Sat, Sep 20 from St. Louis to Tri-Cities, returning Sun, Sep 21, priced at $291 found 2 days ago
Delta
Wed, Sep 10 - Sun, Sep 14
STL
St. Louis
TRI
Tri-Cities
$292 Roundtrip, found 3 days ago
$292
Roundtrip
found 3 days ago
Select Delta flight, departing Wed, Sep 10 from St. Louis to Tri-Cities, returning Sun, Sep 14, priced at $292 found 3 days ago
Delta
Mon, Aug 18 - Thu, Aug 21
STL
St. Louis
TRI
Tri-Cities
$294 Roundtrip, found 1 day ago
$294
Roundtrip
found 1 day ago
Select Delta flight, departing Mon, Aug 18 from St. Louis to Tri-Cities, returning Thu, Aug 21, priced at $294 found 1 day ago
Delta
Thu, Aug 14 - Mon, Aug 18
STL
St. Louis
TRI
Tri-Cities
$299 Roundtrip, found 1 day ago
$299
Roundtrip
found 1 day ago
Select Delta flight, departing Thu, Aug 14 from St. Louis to Tri-Cities, returning Mon, Aug 18, priced at $299 found 1 day ago
Delta
Sun, Sep 7 - Tue, Sep 23
STL
St. Louis
TRI
Tri-Cities
$307 Roundtrip, found 3 days ago
$307
Roundtrip
found 3 days ago
Select Delta flight, departing Sun, Sep 7 from St. Louis to Tri-Cities, returning Tue, Sep 23, priced at $307 found 3 days ago
Delta
Sat, Aug 9 - Tue, Aug 26
STL
St. Louis
TRI
Tri-Cities
$308 Roundtrip, found 3 days ago
$308
Roundtrip
found 3 days ago
Select Delta flight, departing Sat, Aug 9 from St. Louis to Tri-Cities, returning Tue, Aug 26, priced at $308 found 3 days ago
American Airlines
Mon, Aug 11 - Mon, Aug 18
STL
St. Louis
TRI
Tri-Cities
$314 Roundtrip, found 1 day ago
$314
Roundtrip
found 1 day ago
Select American Airlines flight, departing Mon, Aug 11 from St. Louis to Tri-Cities, returning Mon, Aug 18, priced at $314 found 1 day ago

Alternative airports near Blountville

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Tri-Cities Regional TRI. Cheapest option available. Flights from $294
TRI
Tri-Cities Regional
Cheapest
Flights from $294
Flights from St. Louis (STL) to Tri-Cities (TRI)
Origin airport
Lambert-St. Louis Intl.
Destination airport
Tri-Cities Regional
Airlines serving
American Airlines, Delta
Roundtrip price
$286
Distance
462 mi

St. Louis to Tri-Cities Flights

The cheapest times to fly from St. Louis to Tri-Cities

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from St. Louis to Tri-Cities are during the month of December. You can find some of the cheapest flights from St. Louis to Tri-Cities with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from St. Louis to Tri-Cities

Sunday is one of the best days to book for cheap flights from St. Louis to Tri-Cities: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from St. Louis to Tri-Cities

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from St. Louis to Tri-Cities in 2025. You can also book with separate airlines for your outbound and return journeys, from $145 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap St. Louis to Tri-Cities flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your St. Louis to Tri-Cities airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Lambert-St. Louis Intl. Airport (STL) to Tri-Cities Regional Airport (TRI) cost?
Discover the latest flight deals from STL to TRI by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from STL to TRI?
The cheapest flights from STL to TRI are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
What is the cheapest airline that flies from STL to TRI?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that'll take you from STL to TRI. Sort your results by "Price (lowest to highest)" to snap up a great deal.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to Tri-Cities Regional Airport (TRI)?
You'll need to take a flight with a layover when traveling from Lambert-St. Louis Intl. Airport (STL) to Tri-Cities Regional Airport (TRI). There are no daily direct flights on this route. However, just filter your search to include one or more stops to discover the best option for your trip.
What day of the week has the most flights from STL to TRI?
You'll generally find Tuesday the quietest day for flights, while Fridays tend to be the busiest.* However this can change from season to season and during public holidays or peak travel times.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Lambert-St. Louis Intl. Airport (STL) to Tri-Cities Regional Airport (TRI)?
Opt for a flight from Lambert-St. Louis Intl. Airport (STL) to Tri-Cities Regional Airport (TRI) that takes off before 3 PM to reduce the risk of delays and cancellations. Departures after this hour have a 22% higher chance of being canceled, on average.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from Lambert-St. Louis Intl. Airport (STL) to Tri-Cities Regional Airport (TRI) last-minute?
Last-minute fares from STL to TRI are usually more expensive. To lock in the lowest rates, start looking for flights ahead of time. That said, if your travel plans are flexible, it's possible to find a cheap ticket right before your trip.
Is it cheaper to book a STL to TRI flight and hotel package?
Securing a STL to TRI flight and hotel package tends to be cheaper than booking separately. With Expedia, you can enjoy the convenience of organizing your travels all in one place. Pick from our impressive range of hotels and then add activities, car rentals and flights to your booking. Bundle it all together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to Tri-Cities Regional Airport (TRI)?
In most cases, you can modify or cancel your STL to TRI flight. However, additional fees may apply, especially if your booking was made more than 24 hours ago. Double-check your itinerary for the airline's guidelines and fees on flight changes, or if you'd like further information, go to our Customer Service portal.

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*Available to One Key members.