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$284 Cheap Flights from Harrisburg (MDT) to St. Louis (STL)

View $284 flight on Thu, Nov 19, 2026Opens in a new window

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

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

Prices were available within the past 7 days and start at $284 for one-way flights and $320 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Wed, Nov 18 - Sun, Nov 22
MDT
Harrisburg
STL
St. Louis
$320 Roundtrip, found 3 days ago
$320
Roundtrip
found 3 days ago
Select American Airlines flight, departing Wed, Nov 18 from Harrisburg to St. Louis, returning Sun, Nov 22, priced at $320 found 3 days ago
Delta
Tue, Nov 10 - Tue, Nov 17
MDT
Harrisburg
STL
St. Louis
$321 Roundtrip, just found
$321
Roundtrip
just found
Select Delta flight, departing Tue, Nov 10 from Harrisburg to St. Louis, returning Tue, Nov 17, priced at $321 just found
United
Tue, Nov 10 - Tue, Nov 17
MDT
Harrisburg
STL
St. Louis
$321 Roundtrip, just found
$321
Roundtrip
just found
Select United flight, departing Tue, Nov 10 from Harrisburg to St. Louis, returning Tue, Nov 17, priced at $321 just found
United
Mon, Dec 28 - Sat, Jan 2
MDT
Harrisburg
STL
St. Louis
$329 Roundtrip, found 1 day ago
$329
Roundtrip
found 1 day ago
Select United flight, departing Mon, Dec 28 from Harrisburg to St. Louis, returning Sat, Jan 2, priced at $329 found 1 day ago
United
Sat, Oct 31 - Sat, Nov 7
MDT
Harrisburg
STL
St. Louis
$331 Roundtrip, just found
$331
Roundtrip
just found
Select United flight, departing Sat, Oct 31 from Harrisburg to St. Louis, returning Sat, Nov 7, priced at $331 just found
United
Sat, Jan 9 - Sat, Jan 16
MDT
Harrisburg
STL
St. Louis
$333 Roundtrip, found 6 days ago
$333
Roundtrip
found 6 days ago
Select United flight, departing Sat, Jan 9 from Harrisburg to St. Louis, returning Sat, Jan 16, priced at $333 found 6 days ago
United
Tue, Dec 8 - Tue, Dec 15
MDT
Harrisburg
STL
St. Louis
$334 Roundtrip, found 6 days ago
$334
Roundtrip
found 6 days ago
Select United flight, departing Tue, Dec 8 from Harrisburg to St. Louis, returning Tue, Dec 15, priced at $334 found 6 days ago
United
Sat, Nov 7 - Tue, Nov 17
MDT
Harrisburg
STL
St. Louis
$335 Roundtrip, found 8 hours ago
$335
Roundtrip
found 8 hours ago
Select United flight, departing Sat, Nov 7 from Harrisburg to St. Louis, returning Tue, Nov 17, priced at $335 found 8 hours ago
United
Thu, Oct 29 - Tue, Nov 3
MDT
Harrisburg
STL
St. Louis
$335 Roundtrip, found 5 days ago
$335
Roundtrip
found 5 days ago
Select United flight, departing Thu, Oct 29 from Harrisburg to St. Louis, returning Tue, Nov 3, priced at $335 found 5 days ago
United
Wed, Oct 28 - Wed, Nov 4
MDT
Harrisburg
STL
St. Louis
$338 Roundtrip, just found
$338
Roundtrip
just found
Select United flight, departing Wed, Oct 28 from Harrisburg to St. Louis, returning Wed, Nov 4, priced at $338 just found

Alternative airports near St. Louis

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

Select flight to Lambert-St. Louis Intl. STL. Cheapest option available. Average driving time to city center is 20 minutes. Flights from $354
STL
Lambert-St. Louis Intl.
Cheapest
Average driving time to city center20 min
Flights from $354

Find the cheapest month to fly from Harrisburg (MDT) to St. Louis (STL)

May is typically the cheapest month to fly

From $248 - $422 per traveler.

What you need to know for your flight from Harrisburg Intl. to Lambert-St. Louis Intl.

Harrisburg (MDT) to St. Louis (STL) at a glance

Explore a range of options for STL flights from Harrisburg (MDT) to St. Louis (STL) on this domestic short-haul route. Whether you prefer full-service airlines or budget carriers, you can compare itineraries to find the best fit for your budget and schedule. Get ready to discover the iconic sights and vibrant neighborhoods of St. Louis as you plan your travel. Here are the key details for flights from Harrisburg International Airport (MDT) to Lambert-St. Louis International Airport (STL).

  • Fastest flight duration: around 3h 45m in-flight, plus roughly 1h 15m layover with one stop
  • Route distance: roughly 700 miles (1,130 km)
  • Flights per week: around 10 departures on average
  • Typical fares (one-way): economy tickets often range from $125–$405, depending on seasonality and how far ahead you book

Flights from Harrisburg International Airport (MDT) to Lambert-St. Louis International Airport (STL)

Based on recent travel bookings, here are the top airlines favored for flights from Harrisburg to St. Louis, often selected for their one-stop service. Common layover points include O'Hare International Airport (ORD) with a layover of about 1 hour and 30 minutes, Charlotte-Douglas International Airport (CLT) at around 1 hour and 15 minutes, and Detroit Metropolitan Wayne County Airport (DTW), also approximately 1 hour and 15 minutes. This variety allows you to balance price, travel time, and cabin class for the perfect itinerary.

  • American Airlines: This full-service airline provides one-stop travel, with one-way ticket prices generally falling between $125 and $390. It represents around 50% of departures on this route, featuring an in-flight duration of 3 hours and 45 minutes, totaling about 5 hours for the entire journey, including a layover.
  • Delta: As another full-service option, Delta offers one-stop services with one-way fares that typically range from $125 to $375. This carrier is responsible for approximately 30% of flights on this route, with a similar in-flight time of 3 hours and 45 minutes, and an overall travel time nearing 5 hours, including layover.
  • United: United is a full-service airline that provides one-stop travel, with one-way fares usually varying from $130 to $455. It accounts for about 18% of the departures on this route, with an in-flight time of 3 hours and 45 minutes, leading to a total journey duration of roughly 5 hours, including layover.
  • Frontier Airlines: This low-cost carrier offers one-stop service at one-way fares typically between $125 and $205. Frontier constitutes about 2% of departures on this route, with an in-flight time of 3 hours and 45 minutes, resulting in an overall travel duration of around 5 hours, including a layover.

Travelers flying from Harrisburg to St. Louis can enhance their journey by opting for an upgrade. American Airlines provides first-class service on this route.

Best time to fly from Harrisburg (MDT) to St. Louis (STL)

The most popular months for travelers flying from Harrisburg to St. Louis are January, February, and March, when peak temperatures in St. Louis reach up to 46.4°F in March. If you prefer quieter travel, consider September, the least busy and relatively cheaper time to visit with fewer crowds and temperatures around 70.9°F. For better deals, July usually offers the lowest average one-way fare around $185. Flight availability peaks in July, with approximately 12 flights per week, making it easier to find convenient departure times. January, February, and March have the fewest flights, with approximately 9 flights per week.

  • Cheapest time to fly: July usually offers good deals with average one-way fare around $185, roughly 18% cheaper than the yearly average.
  • Another budget-friendly time to fly: May typically offers an average one-way fare of around $210.
  • Most flight options: July has the highest number of flights from Harrisburg to St. Louis, with approximately 12 flights per week, giving you more flexibility in scheduling your trip.
calendar iconMonthtemperature iconTemperaturecrowd level iconDemandflights iconWeekly Flightsprice iconAverage one-way Fare
January31.6°F (-0.2°C)Slightly High9$215
February34.9°F (1.6°C)Slightly High9$240
March46.4°F (8.0°C)Slightly High9$255
April56.1°F (13.4°C)Average11$225
May66.6°F (19.2°C)Average11$210
June76.1°F (24.5°C)Average10$278
July78.6°F (25.9°C)Average12$185
August77.0°F (25.0°C)Slightly Low10$224
September70.9°F (21.6°C)Slightly Low10$222
October58.6°F (14.8°C)Average10$217
November46.2°F (7.9°C)Average11$215
December37.8°F (3.2°C)Slightly Low10$234

*Average one-way fare is based on Expedia flight booking data from January 2025 to April 2026 for the specified route and travel class and may change depending on availability, dates, and demand.

Alternative routes from Harrisburg (MDT) to St. Louis (STL)

  • Harrisburg to St. Louis (HAR-STL): Located roughly 5 miles from Harrisburg International Airport (MDT), Capital City Airport (HAR) serves as a convenient travel option.
  • Lancaster to St. Louis (LNS-STL): Lancaster Airport (LNS) is approximately 25 miles from Harrisburg International Airport (MDT), providing another viable route for travelers.

How to find the best prices for flights from Harrisburg (MDT) to St. Louis (STL)

Getting some of the best deals on flights from Harrisburg to St. Louis is all about timing and flexibility. Here are some key tips to help you save:

  1. Best times to book and fly: cheaper fares are usually found when booking 2 to 8 weeks in advance, although most travelers book within 2 weeks. Evening departures from 6 PM to 12 AM tend to be less expensive, while morning flights from 5 AM to 12 PM are the most popular. Additionally, flying on Saturday generally offers lower prices, but Friday remains the busiest travel day.
  2. Set up price alerts: stay updated on price changes by using Expedia's Price Tracker. Receive alerts when fares drop for your selected route.
  3. Bundle and save: bundle your flight and hotel to save on Expedia, or unlock a hotel deal after booking your flight.*
  4. Compare flight options: use Expedia's search tool to compare airlines, routes, direct vs. non-direct flights, and flight times. You can also sort by price to find the most affordable options.
  5. Stay flexible with dates: being open to different travel days can sometimes help you find better prices on flights and hotels.
  6. Think about luggage: nowadays, it's important to check the airline's baggage policies to find the best value. That may be paying for an additional carry-on bag or booking a ticket with checked luggage included. Either way, double-check your allowance before confirming your booking to avoid excess baggage fees at the airport.

*Members only. Savings vary and are not available on all bundles. Select hotels.

Arriving at Lambert-St. Louis International Airport from Harrisburg International Airport

St. Louis welcomes travelers from Harrisburg with a range of transport options based on price, convenience, and proximity. For departures, Harrisburg International Airport is roughly a 15-minute drive (covering about 12 miles) from central Harrisburg. Here's how to reach St. Louis efficiently:

  • Hotel transfer: Transfers offer a convenient way to reach your hotel in St. Louis, with private rides that can be arranged in advance.
  • Car rental: Renting a car from Lambert-St. Louis International Airport is a great option if you plan to explore and sightsee beyond the city. Browse cheap car rentals at Lambert-St. Louis International Airport on Expedia.
  • Taxi/ride-hailing: Taxis and ride-hailing services may be available from designated pickup areas outside the terminal, check locally on arrival.
  • Public transportation: From Lambert-St. Louis International Airport, Lambert Main Terminal Station, a metro station, is located about 0.1 miles away on foot, providing easy access to public transportation for travelers.

Frequently asked questions

How much does a flight from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) cost?
You can find cheap one-way flights from $284 and cheap return flights from $320 Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) with Expedia. One-way flights typically cost between $261 and $677, and return flights often range between $343 and $1049. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see the cheapest fares first, and use the Price Tracking tool to receive alerts when Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) ticket fares go up or down.*Typical price ranges based on flights available on Expedia in the last year. Prices include multi-airline options.
What is the cheapest month to fly from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
January is the cheapest month to fly from Harrisburg, PA (MDT) to St. Louis, MO (STL), with average return fares around $339. This is about 19% lower than the average price throughout the year, as January follows the holiday season when travel demand decreases. Other cheap months to fly from MDT to STL include August and October.*Averages based on flights available on Expedia in the last year.
Which airlines fly direct from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
Enter MDT to STL and your travel dates, then apply the 'Nonstop' filter to see only direct flights.
What is the cheapest airline that flies from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
Frontier Airlines is one of the cheapest airlines offering connecting flights from Harrisburg, PA (MDT) to St. Louis, MO (STL), with round-trip tickets starting from around $311. Use Expedia's search tool to compare the prices and schedules of airlines that fly this route to find the best option for your plans and budget.*Prices based on flights available on Expedia in the last year.
How do I find cheap flights from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
To find a cheap flight from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.
What is the best time to fly from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
The best time to fly from Harrisburg, PA (MDT) to St. Louis, MO (STL) is in January or August. Both months are the cheapest, with average return flight prices around $339. January is a quieter travel time, while August offers warm weather and plenty of events in St. Louis, making it a great time to visit.*Prices based on flights available on Expedia in the last year.
What is the earliest flight from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
Sort flights by "Departure (earliest)" on Expedia to find the earliest flight from MDT to STL. To compare more early flights, use the "Early Morning" and "Morning" filters in your search.
What are the most popular departure times for flights from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
The most popular departure times for flights from Harrisburg (MDT) to St. Louis (STL) are in the early morning, from 6am to 9am. About 37% of passengers prefer this time window. Many major carriers, including American Airlines, United Airlines, and Delta Airlines, offer flights during this window. This timing works well because it allows you to arrive in St. Louis with a full day ahead of you.
How long does it take to fly from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
Flying from MDT to STL with a connection usually takes about 4 hours 30 minutes, traveling roughly 732 miles. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
First class is available on flights from MDT to STL. First class cabins are available on:

  • American Airlines
  • Delta Air Lines
  • United Airlines

How do I earn miles on a Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) flight with Expedia?
It's easy to earn miles on a Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia.*Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.
What airports do you fly into for St. Louis from Harrisburg Intl. (MDT)?
From Harrisburg Intl. (MDT), you can fly into Lambert-St. Louis Intl. (STL) to reach St. Louis. Some flights may connect through major hubs like Washington Dulles Intl. (IAD), Logan Intl. (BOS), O'Hare Intl. (ORD) before reaching St. Louis. Compare routes and airports on Expedia to find the best flight options for your travel plans.
Is it cheaper to buy a plane ticket from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) at the last minute?
Typically, booking a last minute flight from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.
Is it cheaper to book a Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) flight and hotel package?
Securing a Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) St Louis Vacation Packages is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
If you booked your Harrisburg, PA (MDT-Harrisburg Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) 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 have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more information.

Travel information

Origin airport
Harrisburg Intl.
Destination airport
Lambert-St. Louis Intl.
Airlines serving
American Airlines, Delta, United
Roundtrip price
$319
Distance
732 mi

Book with confidence

Harrisburg to St. Louis Flights

The cheapest times to fly from Harrisburg to St. Louis

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 Harrisburg to St. Louis are during the month of November. You can find some of the cheapest flights from Harrisburg to St. Louis with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Harrisburg to St. Louis

Sunday is one of the best days to book for cheap flights from Harrisburg to St. Louis: 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 Harrisburg to St. Louis

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 Harrisburg to St. Louis in 2026. You can also book with separate airlines for your outbound and return journeys, from $284 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 Harrisburg to St. Louis 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 Harrisburg to St. Louis 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.

 

Harrisburg to St. Louis Flights

*Flight schedules are subject to change.

*Available to One Key members.

 

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