$100 Cheap Flights from Harrisburg (MDT) to St. Louis (STL)

View $100 flight on Sun, May 25, 2025Opens in a new window

Popular airlines from Harrisburg Intl. Airport (MDT) to St. Louis Lambert Intl. Airport (STL)

  • Plan, book, fly with confidence

  • trending down icon
    Be in the know
    Get alerts if flight prices drop or rise*
  • bex rewards loyalty icon
    Book smarter
    Save up to 30% on select hotels after you book a flight*
  • one key icon
    Earn twice
    Earn your airline miles on top of our OneKeyCash
    Learn about One Key
Find available prices by choosing your travel dates.

Cheap Flights from Harrisburg to St. Louis (MDT-STL)

Prices were available within the past 7 days and start at $100 for one-way flights and $188 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Sat, Apr 26 - Wed, May 7
MDT
Harrisburg
STL
St. Louis
$188 Roundtrip, found 13 hours ago
$188
Roundtrip
found 13 hours ago
Select Frontier Airlines flight, departing Sat, Apr 26 from Harrisburg to St. Louis, returning Wed, May 7, priced at $188 found 13 hours ago
Frontier Airlines
Thu, May 8 - Wed, May 14
MDT
Harrisburg
STL
St. Louis
$198 Roundtrip, found 2 hours ago
$198
Roundtrip
found 2 hours ago
Select Frontier Airlines flight, departing Thu, May 8 from Harrisburg to St. Louis, returning Wed, May 14, priced at $198 found 2 hours ago
Frontier Airlines
Sat, Apr 26 - Sat, May 10
MDT
Harrisburg
STL
St. Louis
$208 Roundtrip, found 13 hours ago
$208
Roundtrip
found 13 hours ago
Select Frontier Airlines flight, departing Sat, Apr 26 from Harrisburg to St. Louis, returning Sat, May 10, priced at $208 found 13 hours ago
Delta
Sun, May 25 - Thu, May 29
MDT
Harrisburg
STL
St. Louis
$217 Roundtrip, found 19 hours ago
$217
Roundtrip
found 19 hours ago
Select Delta flight, departing Sun, May 25 from Harrisburg to St. Louis, returning Thu, May 29, priced at $217 found 19 hours ago
Frontier Airlines
Thu, May 1 - Sat, May 10
MDT
Harrisburg
STL
St. Louis
$218 Roundtrip, found 11 hours ago
$218
Roundtrip
found 11 hours ago
Select Frontier Airlines flight, departing Thu, May 1 from Harrisburg to St. Louis, returning Sat, May 10, priced at $218 found 11 hours ago
American Airlines
Sat, Jul 5 - Tue, Jul 8
MDT
Harrisburg
STL
St. Louis
$224 Roundtrip, found 2 days ago
$224
Roundtrip
found 2 days ago
Select American Airlines flight, departing Sat, Jul 5 from Harrisburg to St. Louis, returning Tue, Jul 8, priced at $224 found 2 days ago
Frontier Airlines
Thu, May 22 - Fri, May 30
MDT
Harrisburg
STL
St. Louis
$228 Roundtrip, found 19 hours ago
$228
Roundtrip
found 19 hours ago
Select Frontier Airlines flight, departing Thu, May 22 from Harrisburg to St. Louis, returning Fri, May 30, priced at $228 found 19 hours ago
Frontier Airlines
Thu, May 29 - Sat, Jun 14
MDT
Harrisburg
STL
St. Louis
$231 Roundtrip, found 2 days ago
$231
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Thu, May 29 from Harrisburg to St. Louis, returning Sat, Jun 14, priced at $231 found 2 days ago
Delta
Sun, May 25 - Wed, Jun 4
MDT
Harrisburg
STL
St. Louis
$233 Roundtrip, found 19 hours ago
$233
Roundtrip
found 19 hours ago
Select Delta flight, departing Sun, May 25 from Harrisburg to St. Louis, returning Wed, Jun 4, priced at $233 found 19 hours ago
United
Sat, Feb 28 - Mon, Mar 2
MDT
Harrisburg
STL
St. Louis
$249 Roundtrip, found 2 hours ago
$249
Roundtrip
found 2 hours ago
Select United flight, departing Sat, Feb 28 from Harrisburg to St. Louis, returning Mon, Mar 2, priced at $249 found 2 hours ago

Frequently asked questions

How much does a flight from Harrisburg Intl. Airport (MDT) to Lambert-St. Louis Intl. Airport (STL) cost?
Discover the latest flight deals from MDT to STL 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 MDT to STL?
The cheapest flights from MDT to STL 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 MDT to STL?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that’ll take you from MDT to STL. Sort your results by “Price (lowest to highest)” to snap up a great deal.
How many flights per day from Harrisburg Intl. Airport (MDT) to Lambert-St. Louis Intl. Airport (STL)?
You’ll have to take a flight with a layover when traveling from Harrisburg Intl. Airport (MDT) to Lambert-St. Louis Intl. Airport (STL). There are no daily direct flights on this route. However, simply filter your search to include one or more stops to find an option that works for you.
What day of the week has the most flights from MDT to STL?
Generally you’ll have the most choice when it comes to flights on a Friday. Tuesdays tend to be the quietest.* However, this can change based on the airline, season and other factors.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Harrisburg Intl. Airport (MDT) to Lambert-St. Louis Intl. Airport (STL)?
To avoid potential delays on the Harrisburg Intl. Airport (MDT) to Lambert-St. Louis Intl. Airport (STL) route, fly before 3 PM. Later flights are 22% more likely to be canceled.**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 Harrisburg Intl. Airport (MDT) to Lambert-St. Louis Intl. Airport (STL) last-minute?
Holding off until just before your departure to book your flight from MDT to STL often results in higher prices. Although you may find some last-minute offers, they’re not always guaranteed. Be flexible with your travel plans for a better chance of scoring a bargain.
Is it cheaper to book a MDT to STL flight and hotel package?
You can save money by securing a MDT to STL flight and hotel package compared to booking separately. In fact, travelers could save hundreds of dollars by bundling with Expedia. And it’s easy to manage it all in one place. After choosing your ideal accommodations and flights, you can add extras such as tours, activities and car rentals.
Can I cancel or change the date of my flight from Harrisburg Intl. Airport (MDT) to Lambert-St. Louis Intl. Airport (STL)?
If you booked your MDT to STL flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you purchased, additional charges may apply for changes beyond that time. Airline policies and contact information can be found in your itinerary or confirmation email. Or, go to our Customer Service portal for more information.
*Available to One Key members.