ISP - STL

$88 Find Cheap Flights from Islip to St. Louis

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Islip to St. Louis departing on 5/5. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult

KAYAK searches hundreds of travel sites at once for deals on flights to St. Louis

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Islip to St. Louis, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Islip to St. Louis, as well as popular online travel agencies
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 22% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Flights Deals
Useful Info
Flights Deals

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

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Islip to St. Louis that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.

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

KAYAK's recommended round-trip deals from the most popular airlines that fly from Islip to St. Louis.
Discover the best prices for you by selecting your travel dates on KAYAK.
Frontier Logo
6:48 pm - 12:06 amISP-STL
6h 18m1 stop
Frontier Logo
5:45 pm - 10:12 amSTL-ISP
15h 27m1 stop
$181Frontier
Find Deal
Mon, May 12 - Wed, May 14
Frontier Logo
6:48 pm - 12:06 amISP-STL
6h 18m1 stop
Frontier Logo
5:45 pm - 10:12 amSTL-ISP
15h 27m1 stop
$221Frontier
Find Deal
Thu, May 15 - Sun, May 18
Frontier Logo
8:21 pm - 11:44 pmISP-STL
28h 23m1 stop
Frontier Logo
5:45 pm - 7:41 pmSTL-ISP
24h 56m1 stop
$241Frontier
Find Deal
Fri, May 30 - Sun, Jun 1
Southwest Logo
6:00 am - 10:50 amISP-STL
5h 50m1 stop
Southwest Logo
5:25 am - 5:15 pmSTL-ISP
10h 50m2 stops
$244Southwest
Find Deal
Wed, Jun 18 - Sat, Jun 21
Southwest Logo
6:00 am - 12:35 pmISP-STL
7h 35m2 stops
Southwest Logo
5:25 am - 5:15 pmSTL-ISP
10h 50m2 stops
$249Southwest
Find Deal
Wed, Jun 18 - Sat, Jun 21
Frontier Logo
6:48 pm - 12:06 amISP-STL
6h 18m1 stop
Frontier Logo
5:35 pm - 7:34 pmSTL-ISP
24h 59m1 stop
$251Frontier
Find Deal
Mon, May 19 - Sat, May 24
Frontier Logo
8:21 pm - 11:44 pmISP-STL
28h 23m1 stop
Frontier Logo
5:45 pm - 7:34 pmSTL-ISP
24h 49m1 stop
$261Frontier
Find Deal
Fri, May 23 - Tue, May 27
Frontier Logo
6:48 pm - 12:06 amISP-STL
6h 18m1 stop
Frontier Logo
5:45 pm - 7:34 pmSTL-ISP
24h 49m1 stop
$271Frontier
Find Deal
Mon, May 19 - Thu, May 22
Southwest Logo
6:00 am - 10:50 amISP-STL
5h 50m1 stop
Southwest Logo
6:05 am - 11:35 amSTL-ISP
4h 30m1 stop
$278Southwest
Find Deal
Wed, Jun 18 - Sat, Jun 21
Frontier Logo
8:21 pm - 11:52 pmISP-STL
28h 31m1 stop
Frontier Logo
5:45 pm - 7:26 pmSTL-ISP
24h 41m1 stop
$291Frontier
Find Deal
Thu, May 22 - Mon, May 26
Useful Info

KAYAK's insights & trends for Islip to St. Louis flights

Get data-powered insights and trends into flights from Islip to St. Louis to help you find the cheapest flights, the best time to fly and much more.

Which airlines provide the cheapest flights from Islip to St. Louis?

The cheapest round-trip price for the route for each airline clicked by KAYAK users in the last 72 hours.

In the past 3 days, the cheapest round-trip tickets from Islip to St. Louis were found on Frontier ($181) and Southwest ($244).

Find deals

Good to know

Cheapest flight$88
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.

FAQs for booking flights from Islip to St. Louis

  • What is the cheapest flight from Islip to St. Louis?

    In the last 3 days, the lowest price for a flight from Islip to St. Louis was $88 for a one-way ticket and $181 for a round-trip.

  • Do I need a passport to fly between Islip and St. Louis?

    A passport is not required to fly from Islip to St. Louis.

  • Which airports will I be using when flying from Islip to St. Louis?

    Islip airport is called Islip Long Island and the only airport in St. Louis is Lambert-St Louis.

  • Which aircraft models fly most regularly from Islip to St. Louis?

    We unfortunately don’t have that data for this specific route.

  • How does KAYAK find such low prices on flights from Islip to St. Louis?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Islip to St. Louis.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Islip to St. Louis?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to St. Louis from Islip is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Islip to St. Louis?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to St. Louis with an airline and back to Islip with another airline. Booking your flights between Islip and STL can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Islip to St. Louis?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to St. Louis from Islip up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Top airline flying from Islip to St. Louis

 
See real verified KAYAK customer reviews for airlines flying from Islip to St. Louis. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Islip to St. Louis? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4294 reviews
7.1Food
8.0Comfort
8.6Crew
7.6Entertainment
8.2Boarding
Airline reviews

It is southwest seat was ok. Not the most comfortable seat

8.0 ExcellentJohn, Apr 2025PVD - FLL
Read more Southwest reviews

It is southwest seat was ok. Not the most comfortable seat

I’ve always loved Southwest. No issues at all. I was flying standby and the gate agent was extremely friendly and helpful. Boarding was smooth and I was able to get a window seat in the emergency exit row. Crew was fantastic! They were very professional and accommodating. We had to divert from our destination due to weather but the flight crew kept everyone at ease and informed us of all pertinent information. Excellent flight

The price of the tickets isn't matching the flight experience. No matter how long the flight is, you're only getting pretzels. The flight attendants looked unkept and over it.

Plz don't take away free bags and free seating

The seats were a bit cramped and worn, but otherwise okay.

I would have liked to arrive on time - not 5 hours late!

After a 3 hour layover in Denver my flight was delayed over 5 hours! No explanation; no assistance; no offer to provide compensation; no one at Southwest was willing to offer any assistance. 8 hours in the Denver airport - ridiculous!

It was a perfect flight in all aspects! Both legs!

Only one drink pass through the cabin for a 4 hour flight. Quite rough and bumpy landing.

Boarding process, crew were good. But the seats were so uncomfortable that was all I could focus on. I literally had to sit forward so that all 3 of us could fit in row. I will try to avoid Southwest in the future for any flights over 60 minutes.

Everything you need to know for your flight from Islip to St. Louis

Information on your arrival and departure airports

St. Louis (STL)
Islip (ISP)

Not what you’re looking for? Find thousands of other hotels, flights, car rentals and package deals with KAYAK.