STL - ISP

$98 Find Cheap Flights from St. Louis to Islip

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from St. Louis to Islip departing on 5/11. 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
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Islip

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Islip, 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 St. Louis to Islip, as well as popular online travel agencies
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Everything you should know

Cheapest round-trip
$270
Frontier
Mon 6/8Thu 6/11
STL - ISP • 2 stops
Cheapest one-way
$98
Frontier
Mon 5/11
STL - ISP • 1 stop
Top airlines
Cheapest • from $270 (round-trip)
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Nonstop flights
Not available
There are currently no direct flights between St. Louis and Islip. You'll need at least 1 connection.
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We hope you love your trip to Islip!
Flight Deals
Booking Insights
Flight Deals

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

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from St. Louis to Islip 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.
Discover the best prices for you by selecting your travel dates on KAYAK.

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

Mon, Jun 8 - Thu, Jun 11
Frontier Logo
5:27 pm - 3:56 pm
STL
-
ISP
21h 29m
2 stops
Frontier Logo
10:48 am - 12:09 am
ISP
-
STL
14h 21m
1 stop
$270Frontier
Thu, May 14 - Mon, May 18
Frontier Logo
6:55 pm - 10:05 am
STL
-
ISP
38h 10m
2 stops
Frontier Logo
11:00 am - 12:21 am
ISP
-
STL
14h 21m
1 stop
$287Frontier
Mon, Jun 8 - Thu, Jun 11
Frontier Logo
11:38 am - 3:56 pm
STL
-
ISP
27h 18m
1 stop
Frontier Logo
10:48 am - 12:09 am
ISP
-
STL
14h 21m
1 stop
$291Frontier
Thu, May 14 - Mon, May 18
Frontier Logo
4:19 pm - 10:05 am
STL
-
ISP
16h 46m
1 stop
Frontier Logo
11:00 am - 12:21 am
ISP
-
STL
14h 21m
1 stop
$349Frontier
Tue, May 12 - Sat, May 16
Frontier Logo
6:51 pm - 10:27 am
STL
-
ISP
38h 36m
2 stops
Frontier Logo
11:00 am - 12:21 am
ISP
-
STL
14h 21m
1 stop
$373Frontier
Mon, Jun 8 - Thu, Jun 11
Southwest Logo
4:25 pm - 11:35 pm
STL
-
ISP
6h 10m
2 stops
Southwest Logo
12:30 pm - 6:30 pm
ISP
-
STL
7h 00m
2 stops
$385Southwest
Thu, May 14 - Sun, May 17
Southwest Logo
5:00 am - 12:05 pm
STL
-
ISP
6h 05m
1 stop
Southwest Logo
5:15 am - 10:20 am
ISP
-
STL
6h 05m
1 stop
$394Southwest
Thu, May 14 - Sun, May 17
Southwest Logo
5:00 am - 12:05 pm
STL
-
ISP
6h 05m
1 stop
Southwest Logo
6:05 am - 2:35 pm
ISP
-
STL
9h 30m
2 stops
$409Southwest
Tue, May 12 - Sat, May 16
Southwest Logo
6:35 am - 11:55 am
STL
-
ISP
4h 20m
1 stop
Southwest Logo
4:25 pm - 10:20 pm
ISP
-
STL
6h 55m
1 stop
$411Southwest
Thu, May 14 - Sun, May 17
Southwest Logo
7:20 am - 4:30 pm
STL
-
ISP
8h 10m
2 stops
Southwest Logo
6:05 am - 2:35 pm
ISP
-
STL
9h 30m
2 stops
$427Southwest
Booking Insights

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

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

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

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 St. Louis to Islip were found on Frontier ($270) and Southwest ($385).

Good to know

Cheapest flight$98
Flight from St. Louis to Islip

When to book flights from St. Louis to Islip

Are your dates flexible? Find out the best times to travel from St. Louis to Islip 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 St. Louis to Islip

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

    In the last 3 days, the lowest price for a flight from St. Louis to Islip was $98 for a one-way ticket and $270 for a round-trip.

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

    No, a passport isn't needed to fly from St. Louis to Islip. However, local authorities might ask for an official ID.

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

    When flying out of St. Louis you will be using Lambert-St Louis. You will be landing at Islip, also known as Islip Long Island.

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

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

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

    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 St. Louis to Islip.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Islip from St. Louis 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 St. Louis to Islip?

    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 Islip with an airline and back to St. Louis with another airline. Booking your flights between St. Louis and ISP 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 St. Louis to Islip?

    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 Islip from St. Louis up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top airline flying from St. Louis to Islip

 
See real verified KAYAK customer reviews for airlines flying from St. Louis to Islip. 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 St. Louis to Islip? 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 4314 reviews
8.6Crew
7.5Entertainment
7.0Food
8.1Boarding
8.0Comfort
Airline reviews

The entire experience from boarding to landing was amazing! The crew were very friendly. Will definitely be back.

10.0 Excellentlarry, Apr 2026
LGB - PHX
Read more Southwest reviews

The entire experience from boarding to landing was amazing! The crew were very friendly. Will definitely be back.

no service at all due to turbulence. they should've at least given us snacks, there were only 10 people on the entire flight.

First time I've had to use the disabled accommodations. And I could not have had a better experience with Southwest, i was having trouble getting from one terminal to another due to my heart failure. And the next thing I know a Southwest agent had made sure. I had a wheelchair at all my flights. Can't thank them enough.

Delayed flight, lack of information, boarding process is a mess as is the carryon luggage causing issues when leaving the plane….just a poor experience.

Comfortable. Easy. No problems. Just wish they had gf options for snacks.

The crew was very kind and made going to Hawaii relaxing and fun to look forward to! Thank you Southwest for a pleasant flight!

This leg was much better, but we did have to have a 3 hour lay o er after coming from a very exhausting hiccup with our flight from BNA to Den

We waited in the airplane for over 45 min for a southwest employee to make the flight. This cause over half the plane to miss their connecting flight in Denver. When we confronted the desk upon arrival, they told us the only flight they had was the next day leaving at 8:50 pm!!! Or they offered to get us to Burbank or LA, but after that we were on our own to get back to Santa Barbara. I paid for a flight from sba to bna bna to sba. My re entry into mom mode has been 💯 rough because of southwest mistake with my flight. And now I’m leaving to Reno tomorrow for a vballl tournament and just discovered that my leg in Vegas has me and my 3 kids on a stand by flight even though I had booked these ticket last year November!! Do better southwest!

Southwest is kind of a slum airline. It’s gotten more expensive over the years for less and less service. I am a Southwest Chase Visa card holder and was forced to choose a seat in the 26th row in the middle seat. However my wife who is a rewards member but doesn’t hold a card or anything else, gets randomly assigned a normally paid seat in row 6! How does that work?

For the first time in a long time, the Wi-Fi actually worked the entire flight! The flight crew was amazing as usual.

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

Information on your arrival and departure airports