$137+ Cheap flights from St. Louis to Harlingen (STL - HRL)
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 1/1. Fares are subject to change and may not be available on all flights or dates of travel.
STL — HRL
Sep 10 — Sep 171
Round-trip
1 adult, Economy
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Find cheap flights from St. Louis to Harlingen with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from St. Louis to Harlingen
Cheapest
Best
Last-minute
One-way
Cheapest flights from St. Louis to HarlingenExplore the most affordable flight options available from St. Louis to Harlingen. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 11, 2026.
Explore the most affordable flight options available from St. Louis to Harlingen. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 11, 2026.
This Southwest deal was found by Cheapflights users on 8/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/95:30 pm -
1 stop4h 20m
Wed 9/167:25 am -
1 stop5h 15m
Deal found 8/8![Southwest logo]()
$285
This American Airlines deal was found by Cheapflights users on 8/10. 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.
Sat 10/245:40 am -
1 stop4h 28m
Fri 10/306:42 pm -
1 stop17h 20m
Deal found 8/10![American Airlines logo]()
$317
This American Airlines deal was found by Cheapflights users on 8/6. 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.
Sat 9/55:11 pm -
1 stop5h 43m
Fri 9/115:28 pm -
1 stop6h 15m
Deal found 8/6![American Airlines logo]()
$322
This American Airlines deal was found by Cheapflights users on 8/9. 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 10/165:40 am -
1 stop4h 28m
Mon 10/192:46 pm -
1 stop7h 13m
Deal found 8/9![American Airlines logo]()
$329
This Southwest deal was found by Cheapflights users on 8/9. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/163:20 pm -
2 stops7h 30m
Mon 10/196:30 pm -
1 stop3h 55m
Deal found 8/9![Southwest logo]()
$334
This Southwest deal was found by Cheapflights users on 8/6. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/55:15 am -
1 stop6h 40m
Fri 9/1111:55 am -
2 stops7h 55m
Deal found 8/6![Southwest logo]()
$337
This Southwest deal was found by Cheapflights users on 8/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/275:15 am -
1 stop6h 05m
Mon 8/311:55 pm -
1 stop5h 25m
Deal found 8/8![Southwest logo]()
$354
Best flights from St. Louis to HarlingenDiscover carefully curated flight deals from St. Louis to Harlingen that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated August 11, 2026.
Discover carefully curated flight deals from St. Louis to Harlingen that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated August 11, 2026.
This United Airlines deal was found by Cheapflights users on 8/10. 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.
Fri 1/16:15 am -
1 stop7h 09m
Wed 1/65:16 pm -
1 stop4h 50m
Deal found 8/10![United Airlines logo]()
$262
This Southwest deal was found by Cheapflights users on 8/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/95:30 pm -
1 stop4h 20m
Wed 9/167:25 am -
1 stop5h 15m
Deal found 8/8![Southwest logo]()
$285
This American Airlines deal was found by Cheapflights users on 8/6. 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.
Sat 10/2412:46 pm -
1 stop5h 26m
Fri 10/302:46 pm -
1 stop18h 32m
Deal found 8/6![American Airlines logo]()
$342
This United Airlines deal was found by Cheapflights users on 8/10. 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.
Wed 2/35:00 am -
2 stops10h 34m
Sat 2/69:20 am -
2 stops7h 36m
Deal found 8/10![United Airlines logo]()
$307
This Southwest deal was found by Cheapflights users on 8/10. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 1/15:30 am -
2 stops6h 40m
Wed 1/61:00 pm -
2 stops6h 45m
Deal found 8/10![Southwest logo]()
$321
This Southwest deal was found by Cheapflights users on 8/10. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 1/15:30 am -
2 stops6h 40m
Thu 1/76:50 am -
1 stop6h 40m
Deal found 8/10![Southwest logo]()
$328
This Southwest deal was found by Cheapflights users on 8/6. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/55:15 am -
1 stop6h 40m
Fri 9/1111:55 am -
2 stops7h 55m
Deal found 8/6![Southwest logo]()
$337
This Southwest deal was found by Cheapflights users on 8/9. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/163:20 pm -
2 stops7h 30m
Mon 10/196:30 pm -
2 stops6h 05m
Deal found 8/9![Southwest logo]()
$339
Last-minute flights from St. Louis to HarlingenDiscover last-minute flight deals from St. Louis to Harlingen. Data last updated August 11, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Harlingen. Data last updated August 11, 2026 and is based on user searches.
This Southwest deal was found by Cheapflights users on 8/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/275:15 am -
1 stop6h 05m
Mon 8/311:55 pm -
1 stop5h 25m
Deal found 8/8![Southwest logo]()
$354
This Southwest deal was found by Cheapflights users on 8/10. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/45:15 am -
1 stop6h 05m
Fri 10/26:30 pm -
1 stop3h 55m
Deal found 8/10![Southwest logo]()
$381
This American Airlines deal was found by Cheapflights users on 8/6. 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.
Sat 9/55:11 pm -
1 stop5h 43m
Fri 9/115:28 pm -
1 stop6h 15m
Deal found 8/6![American Airlines logo]()
$322
This Southwest deal was found by Cheapflights users on 8/6. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/55:15 am -
1 stop6h 40m
Fri 9/1111:55 am -
2 stops7h 55m
Deal found 8/6![Southwest logo]()
$337
This Southwest deal was found by Cheapflights users on 8/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/95:30 pm -
1 stop4h 20m
Wed 9/167:25 am -
1 stop5h 15m
Deal found 8/8![Southwest logo]()
$285
One-way flights from St. Louis to HarlingenSearch for one-way flight options from St. Louis to Harlingen. Find affordable one-way fares based on user searches. Data last updated August 11, 2026.
Search for one-way flight options from St. Louis to Harlingen. Find affordable one-way fares based on user searches. Data last updated August 11, 2026.
This United Airlines deal was found by Cheapflights users on 8/10. 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.
Fri 1/16:15 am -
1 stop7h 09m
Deal found 8/10![United Airlines logo]()
$137
Find flight deals from St. Louis to Harlingen
Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Harlingen (HRL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated August 11, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $285 (Southwest) |
One-way from | $137 (United Airlines) |
Popular in | July |
Cheapest in | January |
Average price | $428 |
Cheapflights Fare Finder
Customize your flight search to find flights from St. Louis to Harlingen 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 August 11, 2026.
Use the filters below to find and compare flights from St. Louis to Harlingen that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
St. LouisHarlingen
STL Lambert-St Louis - HRL Harlingen Valley Intl
STLHRL
Lambert-St Louis
Fri 1/1
6:15 am-1:24 pm
1 stop7h 09m
Harlingen Valley Intl
Wed 1/6
5:16 pm-10:06 pm
1 stop4h 50m
$262
Quickest round-trip
St. LouisHarlingen
STL Lambert-St Louis - HRL Harlingen Valley Intl
STLHRL
Lambert-St Louis
Wed 9/9
5:30 pm-9:50 pm
1 stop4h 20m
Harlingen Valley Intl
Wed 9/16
7:25 am-12:40 pm
1 stop5h 15m
$285
St. LouisHarlingen
STL Lambert-St Louis - HRL Harlingen Valley Intl
STLHRL
Lambert-St Louis
Wed 2/3
5:00 am-3:34 pm
2 stops10h 34m
Harlingen Valley Intl
Sat 2/6
9:20 am-4:56 pm
2 stops7h 36m
$307
St. LouisHarlingen
STL Lambert-St Louis - HRL Harlingen Valley Intl
STLHRL
Lambert-St Louis
Fri 1/1
5:30 am-12:10 pm
2 stops6h 40m
Harlingen Valley Intl
Wed 1/6
1:00 pm-7:45 pm
2 stops6h 45m
$321
St. LouisHarlingen
STL Lambert-St Louis - HRL Harlingen Valley Intl
STLHRL
Lambert-St Louis
Fri 1/1
5:30 am-12:10 pm
2 stops6h 40m
Harlingen Valley Intl
Thu 1/7
6:50 am-1:30 pm
1 stop6h 40m
$328
St. LouisHarlingen
STL Lambert-St Louis - HRL Harlingen Valley Intl
STLHRL
Lambert-St Louis
Sat 9/5
5:15 am-11:55 am
1 stop6h 40m
Harlingen Valley Intl
Fri 9/11
11:55 am-7:50 pm
2 stops7h 55m
$337
St. LouisHarlingen
STL Lambert-St Louis - HRL Harlingen Valley Intl
STLHRL
Lambert-St Louis
Fri 10/16
3:20 pm-10:50 pm
2 stops7h 30m
Harlingen Valley Intl
Mon 10/19
6:30 pm-12:35 am
2 stops6h 05m
$339
St. LouisHarlingen
STL Lambert-St Louis - HRL Harlingen Valley Intl
STLHRL
Lambert-St Louis
Sat 10/24
12:46 pm-6:12 pm
1 stop5h 26m
Harlingen Valley Intl
Fri 10/30
2:46 pm-9:18 am
1 stop18h 32m
$342
Cheapest one-way
Quickest one-way
St. LouisHarlingen
STL Lambert-St Louis - HRL Harlingen Valley Intl
STLHRL
Lambert-St Louis
Fri 1/1
6:15 am-1:24 pm
1 stop7h 09m
$137
Sorted by cheapest first
Compare providers for flights from St. Louis to Harlingen
Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from St. Louis to Harlingen in August.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars |
- Most accurate provider: When it comes to deals on St. Louis-Harlingen flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Harlingen flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Harlingen flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on St. Louis-Harlingen flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Harlingen flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.
Best time to book a flight from St. Louis to Harlingen
Have a flexible travel schedule? Discover the best time to fly to Harlingen from St. Louis with our price prediction graph.
STL-HRL
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.
Reviews of airlines servicing Harlingen
Get insights into the airlines that provide service to Harlingen. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Harlingen. Reviews last updated August 11, 2026.
Get a feel of what it's like to fly with Southwest and American Airlines from St. Louis to Harlingen by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Crew
8.6
Overall
8.0
Food
7.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreMike,Aug 2025
OKC - AUS
Crew
8.6
Overall
8.0
Food
7.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreMike,Aug 2025
OKC - AUS
Crew
8.6
Overall
8.0
Food
7.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreMike,Aug 2025
OKC - AUS
Related info for your journey
Find useful and relevant information for your journey from St. Louis to Harlingen. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
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Complete your trip
Complete your trip to Harlingen by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from St. Louis to Harlingen by cabin class
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Other flights to Harlingen
Explore flights to Harlingen departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on August 11, 2026.
St. Louis and Harlingen flights
Browse other St. Louis and Harlingen flight options. Last updated on August 11, 2026.
Other flights from St. Louis
Browse through other flights departing from St. Louis. Flights are based on user searches made on Cheapflights and were last updated on August 11, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Top 2 airlines flying from St. Louis to Harlingen
Discover the top 2 airlines that operate flights from St. Louis to Harlingen. 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 August 11, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$212 | Average$390 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$244 | Average$417 | FlexibilityNo cancel fee | On-time63% |