Which airports can I use when flying from Islip to St. Louis?

Flights from Islip to St. Louis usually depart from Islip Long Island (ISP) and arrive at Lambert-St Louis (STL).

What cabin classes can I book on flights from Islip to St. Louis?

Only Economy Class is available on flights from Islip to St. Louis.

Which airports do connecting flights from Islip to St. Louis pass through?

Most connecting flights from Islip to St. Louis pass through Baltimore/Washington (BWI), which handles 100% of one-stop traffic on this route. Other layover airports each see under 5%.

Can I save money by using flexible dates for flights from Islip to St. Louis?

Yes. Being flexible with your travel dates can save you up to 21% on the Islip to St. Louis route. Wednesday is the cheapest departure day at $324 round-trip on average, while Friday is the most expensive at $406, a difference of $82. KAYAK's flexible dates feature shows options up to 3 days before and after your selected dates, making it easier to compare nearby fares.

What popular places can I visit in St. Louis?

Some of the most popular sights in St. Louis are Downtown St. Louis, Busch Stadium and Enterprise Center. These are among the most viewed places in St. Louis on KAYAK.

How long is a flight from Islip to St. Louis?

A nonstop flight from Islip to St. Louis takes 0h 00m, covering 926 miles.

Do I need a passport to fly from Islip to St. Louis?

No, a passport is not required for this domestic route, but you will need a real ID-compliant driver's license, a state ID, or another TSA-accepted form of identification.

Have flight prices from Islip to St. Louis changed much recently?

Yes. Based on fares seen in the past 5 days, round-trip prices on this route showed a wide range, from about $356 to $776. That means the highest observed fare was about 2x higher than the lowest one.

How are flight prices from Islip to St. Louis looking right now?

One-way fares from Islip to St. Louis are currently higher than usual. Average one-way flight prices are about $160, which is 10% above the typical average for this route.

What is the time difference between Islip and St. Louis?

St. Louis is 1 hour behind Islip (Central Time vs Eastern Time). Plan for the time shift when scheduling connections or first-day activities.

What car rental options are available at Lambert-St Louis Airport (STL)?

Lambert-St Louis Airport (STL) hosts 5 major car rental companies, with daily rates starting from around $31 for economy cars. Top options include: • Hertz • Budget • Alamo • Enterprise Rent-A-Car • Payless

What is the cheapest airline to fly from Islip to St. Louis?

Southwest ($366) offered the cheapest round-trip ticket from Islip to St. Louis in the last 5 days.

What is the cheapest layover airport when flying from Islip to St. Louis?

Flights via Baltimore/Washington (BWI) offer the most affordable fares, with an average round-trip price of $317. Based on KAYAK data over the past 3 months.

When flying from Islip to St. Louis which airport offers the shortest layover?

Baltimore/Washington (BWI) had the shortest average connection time for Islip to St. Louis layovers at 228 minutes over the past 3 months.

$122 CHEAP FLIGHTS from Islip to St. Louis (ISP - STL)

Save 21% or more on flights. Compare deals from all over the web.

Never overpay with our price tracking tools.

Filter searches by price, airline and more to find your best flights.

Cheapest round-trip

$366

Typical prices: $324-$359

Southwest

Tue 10/9Sat 10/13

ISP - STL • 1 stop

Cheapest one-way

$122

Typical prices: $129-$164

Southwest

Sun 10/7

ISP - STL • 1 stop

Nonstop flights

Not available

There are currently no direct flights between Islip and St. Louis. You'll need to take a connecting flight to reach the destination.

Insights

Start a new search

KAYAK searches 100s of sites at once to find you the best travel deals.

We hope you love your trip to St. Louis!

Flight Deals

Cheap Flights from Islip to St. Louis (ISP-STL)

Discover the best prices for you by selecting your travel dates on KAYAK.

Round-trip

One-way

Recent round-trip flight deals from Islip to St. Louis

Fri, Oct 9 - Tue, Oct 13

3:10 pm - 11:20 pmISP Islip Long Island-STL Lambert-St Louis

9h 10m1 stop Baltimore/Washington

3:20 pm - 10:40 pmSTL Lambert-St Louis-ISP Islip Long Island

6h 20m1 stop Baltimore/Washington

$366Southwest

Fri, Oct 9 - Tue, Oct 13

3:10 pm - 11:20 pmISP Islip Long Island-STL Lambert-St Louis

9h 10m1 stop Baltimore/Washington

5:25 am - 3:30 pmSTL Lambert-St Louis-ISP Islip Long Island

9h 05m2 stops Orlando West Palm Beach President Donald J. Trump Intl

$372Southwest

Fri, Oct 9 - Tue, Oct 13

6:00 am - 12:15 pmISP Islip Long Island-STL Lambert-St Louis

7h 15m2 stops Baltimore/Washington Chicago Midway

5:25 am - 3:30 pmSTL Lambert-St Louis-ISP Islip Long Island

9h 05m2 stops Orlando West Palm Beach President Donald J. Trump Intl

$397Southwest

Sat, Sep 26 - Wed, Sep 30

3:15 pm - 8:45 pmISP Islip Long Island-STL Lambert-St Louis

6h 30m1 stop Baltimore/Washington

1:40 pm - 9:10 pmSTL Lambert-St Louis-ISP Islip Long Island

6h 30m1 stop Baltimore/Washington

$464Southwest

Sat, Sep 26 - Wed, Sep 30

3:15 pm - 8:45 pmISP Islip Long Island-STL Lambert-St Louis

6h 30m1 stop Baltimore/Washington

10:45 am - 9:10 pmSTL Lambert-St Louis-ISP Islip Long Island

9h 25m2 stops Orlando Baltimore/Washington

$469Southwest

Sat, Sep 26 - Wed, Sep 30

5:30 am - 12:35 pmISP Islip Long Island-STL Lambert-St Louis

8h 05m2 stops Baltimore/Washington Atlanta Hartsfield-Jackson

10:45 am - 9:10 pmSTL Lambert-St Louis-ISP Islip Long Island

9h 25m2 stops Orlando Baltimore/Washington

$475Southwest

Booking Insights

Price, demand and travel trends for Islip to St. Louis flights

Use KAYAK data on prices, travel dates, airlines and seasonal trends to compare options and book flights from Islip to St. Louis with more confidence.

Prices

Airlines

Layovers

How much is a round-trip flight from Islip to St. Louis?

Round-trip flights from Islip to St. Louis start at $366. Prices are above average for this route right now, with typical round-trip fares ranging from $324 to $359. The lowest price found in the past 5 days was $366 on Southwest.

Find deals

Cheapest flight	$122

Flight from Islip to St. Louis

When to book flights from Islip to St. Louis

Are your dates flexible? Find out the best times to travel from Islip to St. Louis based on our flight data from the last year. Discover the cheapest month and even day to fly.

Estimated round-trip price

KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

Which airports can I use when flying from Islip to St. Louis?
Flights from Islip to St. Louis usually depart from Islip Long Island (ISP) and arrive at Lambert-St Louis (STL).
What cabin classes can I book on flights from Islip to St. Louis?
Only Economy Class is available on flights from Islip to St. Louis.
Which airports do connecting flights from Islip to St. Louis pass through?
Most connecting flights from Islip to St. Louis pass through Baltimore/Washington (BWI), which handles 100% of one-stop traffic on this route. Other layover airports each see under 5%.
Can I save money by using flexible dates for flights from Islip to St. Louis?
Yes. Being flexible with your travel dates can save you up to 21% on the Islip to St. Louis route. Wednesday is the cheapest departure day at $324 round-trip on average, while Friday is the most expensive at $406, a difference of $82. KAYAK's flexible dates feature shows options up to 3 days before and after your selected dates, making it easier to compare nearby fares.
What popular places can I visit in St. Louis?
Some of the most popular sights in St. Louis are Downtown St. Louis, Busch Stadium and Enterprise Center. These are among the most viewed places in St. Louis on KAYAK.
How long is a flight from Islip to St. Louis?
A nonstop flight from Islip to St. Louis takes 0h 00m, covering 926 miles.
Do I need a passport to fly from Islip to St. Louis?
No, a passport is not required for this domestic route, but you will need a real ID-compliant driver's license, a state ID, or another TSA-accepted form of identification.
Have flight prices from Islip to St. Louis changed much recently?
Yes. Based on fares seen in the past 5 days, round-trip prices on this route showed a wide range, from about $356 to $776. That means the highest observed fare was about 2x higher than the lowest one.
How are flight prices from Islip to St. Louis looking right now?
One-way fares from Islip to St. Louis are currently higher than usual. Average one-way flight prices are about $160, which is 10% above the typical average for this route.
What is the time difference between Islip and St. Louis?
St. Louis is 1 hour behind Islip (Central Time vs Eastern Time). Plan for the time shift when scheduling connections or first-day activities.
What car rental options are available at Lambert-St Louis Airport (STL)?
Lambert-St Louis Airport (STL) hosts 5 major car rental companies, with daily rates starting from around $31 for economy cars. Top options include:
• Hertz
• Budget
• Alamo
• Enterprise Rent-A-Car
• Payless

If your dates can be flexible, aim for a Wednesday departure instead of Friday. On this route, Wednesday flights average $324 - about $82 less than Friday (20% savings) based on the last 12 months.
If you're arriving late at night and need somewhere to stay, check out these hotels close to Lambert-St Louis Airport.
- Drury Inn & Suites St. Louis Airport
- Renaissance St. Louis Airport Hotel
- DoubleTree by Hilton St. Louis Airport

More options for your flight from Islip to St. Louis

Add a hotel or car rental

Airports

Cabin class

Direct Flights

Origins

Other destinations

Return flight

Complete your trip to St. Louis with a hotel stay or car rental

Car rentals in St. Louis

Hotels in St. Louis

Vacations in St. Louis

ISP - STL

$122 Find Cheap Flights from Islip to St. Louis - Compare and Save

Everything you should know

Cheap Flights from Islip to St. Louis (ISP-STL)

Recent round-trip flight deals from Islip to St. Louis

Recent one-way flight deals from Islip to St. Louis

Price, demand and travel trends for Islip to St. Louis flights

How much is a round-trip flight from Islip to St. Louis?

What is the cheapest airline to fly from Islip to St. Louis?

What is the cheapest layover airport when flying from Islip to St. Louis?

When flying from Islip to St. Louis which airport offers the shortest layover?

Key details for Islip to St. Louis flights

Cheapest flight

When to book flights from Islip to St. Louis

Your Islip to St. Louis flight questions, answered

Your guide to booking Islip to St. Louis flights

More options for your flight from Islip to St. Louis

Complete your trip to St. Louis with a hotel stay or car rental

Information on your arrival and departure airports

Cabin class types available on flights from Islip to St. Louis

Find direct flights to and from Islip and St. Louis

Flights from domestic origins to St. Louis

Flights to other popular destinations

Find deals for your return flight