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Cheap flights from Islip, New York to St. Louis from $79

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Islip, New York to St. Louis departing on 2/6. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from Islip, New York to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
Multiple Airlines Logo
11:50 am - 10:33 pmISP-STL
11h 43m2 stops
Multiple Airlines Logo
5:11 pm - 10:40 amSTL-ISP
16h 29m1 stop
$237Multiple Airlines
Find Deal
mié., ene. 28 - dom., feb. 1
Southwest Logo
3:40 pm - 7:30 pmISP-STL
4h 50m1 stop
Southwest Logo
6:05 am - 12:15 pmSTL-ISP
5h 10m1 stop
$271Southwest
Find Deal
sáb., dic. 6 - lun., dic. 8
Southwest Logo
3:40 pm - 7:30 pmISP-STL
4h 50m1 stop
Southwest Logo
6:05 am - 3:20 pmSTL-ISP
8h 15m1 stop
$276Southwest
Find Deal
sáb., dic. 6 - lun., dic. 8
Southwest Logo
12:40 pm - 7:00 pmISP-STL
7h 20m1 stop
Southwest Logo
5:05 am - 11:55 amSTL-ISP
5h 50m1 stop
$300Southwest
Find Deal
mié., ene. 28 - dom., feb. 1
Southwest Logo
3:45 pm - 9:55 pmISP-STL
7h 10m2 stops
Southwest Logo
6:25 am - 4:25 pmSTL-ISP
9h 00m2 stops
$310Southwest
Find Deal
mié., ene. 28 - dom., feb. 1
Southwest Logo
11:55 am - 8:50 pmISP-STL
9h 55m2 stops
Southwest Logo
6:05 am - 12:15 pmSTL-ISP
5h 10m1 stop
$319Southwest
Find Deal
sáb., dic. 6 - lun., dic. 8
Southwest Logo
11:55 am - 8:50 pmISP-STL
9h 55m2 stops
Southwest Logo
6:05 am - 3:20 pmSTL-ISP
8h 15m1 stop
$325Southwest
Find Deal
sáb., dic. 6 - lun., dic. 8
Southwest Logo
11:55 am - 8:50 pmISP-STL
9h 55m2 stops
Southwest Logo
12:45 pm - 9:40 pmSTL-ISP
7h 55m2 stops
$377Southwest
Find Deal
sáb., dic. 6 - lun., dic. 8
Frontier Logo
8:19 pm - 7:13 amISP-STL
11h 54m1 stop
Frontier Logo
6:00 am - 7:11 pmSTL-ISP
12h 11m1 stop
$1,000Frontier
Find Deal
vie., mar. 27 - dom., mar. 29
Frontier Logo
11:32 am - 11:57 pmISP-STL
13h 25m1 stop
Frontier Logo
10:24 am - 7:30 pmSTL-ISP
8h 06m1 stop
$1,230Frontier
Find Deal
vie., nov. 28 - dom., nov. 30

Southwest flights from Islip, New York to St. Louis

Our best Southwest deals on Islip, New York to St. Louis flight tickets
Southwest
Dec 6
ISP3:40 pmIslip Long Island
4h 50m
1 stop
STL7:30 pmLambert-St Louis
Dec 8
STL6:05 amLambert-St Louis
5h 10m
1 stop
ISP12:15 pmIslip Long Island
$271
Find similar
Southwest
Dec 6
ISP3:40 pmIslip Long Island
4h 50m
1 stop
STL7:30 pmLambert-St Louis
Dec 8
STL6:05 amLambert-St Louis
8h 15m
1 stop
ISP3:20 pmIslip Long Island
$276
Find similar
Southwest
Jan 28
ISP12:40 pmIslip Long Island
7h 20m
1 stop
STL7:00 pmLambert-St Louis
Feb 1
STL5:05 amLambert-St Louis
5h 50m
1 stop
ISP11:55 amIslip Long Island
$300
Find similar

Frontier flights from Islip, New York to St. Louis

Our best Frontier deals on Islip, New York to St. Louis flight tickets
Frontier
Mar 27
ISP8:19 pmIslip Long Island
11h 54m
1 stop
STL7:13 amLambert-St Louis
Mar 29
STL6:00 amLambert-St Louis
12h 11m
1 stop
ISP7:11 pmIslip Long Island
$1,000
Find similar
Frontier
Nov 28
ISP11:32 amIslip Long Island
13h 25m
1 stop
STL11:57 pmLambert-St Louis
Nov 30
STL10:24 amLambert-St Louis
8h 06m
1 stop
ISP7:30 pmIslip Long Island
$1,230
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Islip, New York to St. Louis that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated noviembre 6, 2025.
Use the filters below to find and compare flights from Islip, New York to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

IslipSt. Louis

ISP - STL

ISPSTL

Islip Long Island

mié. 1/28

11:50 am-10:33 pm

2 stops11h 43m

Lambert-St Louis

dom. 2/1

5:11 pm-10:40 am

1 stop16h 29m

$237

IslipSt. Louis

ISP - STL

ISPSTL

Islip Long Island

sáb. 12/6

3:40 pm-7:30 pm

1 stop4h 50m

Lambert-St Louis

lun. 12/8

6:05 am-12:15 pm

1 stop5h 10m

$271

IslipSt. Louis

ISP - STL

ISPSTL

Islip Long Island

sáb. 12/6

3:40 pm-7:30 pm

1 stop4h 50m

Lambert-St Louis

lun. 12/8

6:05 am-3:20 pm

1 stop8h 15m

$276

IslipSt. Louis

ISP - STL

ISPSTL

Islip Long Island

mié. 1/28

12:40 pm-7:00 pm

1 stop7h 20m

Lambert-St Louis

dom. 2/1

5:05 am-11:55 am

1 stop5h 50m

$300

IslipSt. Louis

ISP - STL

ISPSTL

Islip Long Island

mié. 1/28

3:45 pm-9:55 pm

2 stops7h 10m

Lambert-St Louis

dom. 2/1

6:25 am-4:25 pm

2 stops9h 00m

$310

IslipSt. Louis

ISP - STL

ISPSTL

Islip Long Island

sáb. 12/6

11:55 am-8:50 pm

2 stops9h 55m

Lambert-St Louis

lun. 12/8

6:05 am-12:15 pm

1 stop5h 10m

$319

IslipSt. Louis

ISP - STL

ISPSTL

Islip Long Island

sáb. 12/6

11:55 am-8:50 pm

2 stops9h 55m

Lambert-St Louis

lun. 12/8

6:05 am-3:20 pm

1 stop8h 15m

$325

IslipSt. Louis

ISP - STL

ISPSTL

Islip Long Island

sáb. 12/6

11:55 am-8:50 pm

2 stops9h 55m

Lambert-St Louis

lun. 12/8

12:45 pm-9:40 pm

2 stops7h 55m

$377

IslipSt. Louis

ISP - STL

ISPSTL

Islip Long Island

vie. 3/27

8:19 pm-7:13 am

1 stop11h 54m

Lambert-St Louis

dom. 3/29

6:00 am-7:11 pm

1 stop12h 11m

$1,000

IslipSt. Louis

ISP - STL

ISPSTL

Islip Long Island

vie. 11/28

11:32 am-11:57 pm

1 stop13h 25m

Lambert-St Louis

dom. 11/30

10:24 am-7:30 pm

1 stop8h 06m

$1,230

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 11 resultsSorted by cheapest first
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See travel insights to St. Louis from

How to get the cheapest flight ticket from Islip, New York to St. Louis

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Wednesday when prices can be found for as low as $319. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around $439. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Islip, New York in the morning is the least expensive time of day to depart. momondo users have found prices as low as $344 when looking at flights departing in the morning. In the evening is when there is more demand to fly to St. Louis, so prices are often more expensive at around $377 per ticket.

When to book flights from Islip, New York to St. Louis

Are you open to changing your travel dates? Check out the ideal times to fly from Islip, New York to St. Louis according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Islip, New York to St. Louis (ISP to STL) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Islip, New York to St. Louis

Direct flights

None
There are no direct flights from Islip, New York to St. Louis. There are no popular flight routes from Islip, New York to St. Louis.
Search flight deals

  • How far is Islip Long Island to Lambert-St Louis by plane?

    There are 912.8 mi between Islip Long Island and Lambert-St Louis. In terms of flight time, this usually takes a little over 4h 50m.

  • When did momondo last update prices for flights from Islip Long Island Airport to Lambert-St Louis Airport?

    Prices for flights from Islip Long Island Airport to Lambert-St Louis Airport are refreshed on a daily basis.

  • How many operators does momondo search for flights from Islip Long Island Airport to Lambert-St Louis Airport?

  • How old do you have to be to fly from Islip Long Island Airport to Lambert-St Louis Airport?

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Islip Long Island Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The travel and health documents you'll need for your trip to Lambert-St Louis Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Lambert-St Louis Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular airline from Islip, New York to St. Louis?

Best airlines flying from Islip, New York to St. Louis

Compare and see reviews for airlines that fly from Islip, New York to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
SouthwestPriceFrom $259Free CancellationRating
8.0
4,241 reviews
Search Southwest flights

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Hermann
Fairview Heights
Florissant
Maryland Heights
O'Fallon
Wentzville
Fenton
Collinsville
St. Peters
Alton
Farmington
Festus
Glencoe
Edwardsville
Clayton
Eureka
Litchfield
Shrewsbury

Why use momondo?

Why should I use momondo to find a flight deal from Islip to St. Louis?

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Islip to St. Louis. Millions of users trust and use momondo every year so you are in good hands.

Can I find flights from Islip to St. Louis with flexible booking policies on momondo?

Yes. momondo allows you to filter the results for Islip to St. Louis flights to just show those with flexible booking policies.

How can momondo help me find flights from Islip to St. Louis?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Islip to St. Louis.

I’m not ready to book a flight from Islip to St. Louis right now. Can momondo alert me if prices change?

Price alerts on flights to St. Louis from Islip are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.

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sáb. 12/6
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