BOS - SLU

$404 Find Cheap Flights from Boston to Castries - Compare and Save

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Boston to Castries departing on 9/5. 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
1 adult, Economy, 0 bags

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

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

Cheapest round-trip
$869
Multiple Airlines
Wed 9/9Sun 9/13
BOS - SLU • 2 stops
Cheapest one-way
$404
Multiple Airlines
Sat 9/5
BOS - SLU • 2 stops
When to travel
May
Cheapest • 100% price drop
December
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to Castries!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Boston to Castries (BOS-SLU)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Boston to Castries 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 Boston to Castries

Wed, Sep 9 - Sun, Sep 13
Multiple Airlines Logo
6:00 am - 7:00 pm
BOS
-
SLU
13h 00m
2 stops
Multiple Airlines Logo
12:35 pm - 11:55 am
SLU
-
BOS
23h 20m
2 stops
$869Multiple Airlines
Sat, Sep 5 - Wed, Sep 16
Multiple Airlines Logo
7:15 pm - 7:00 pm
BOS
-
SLU
23h 45m
2 stops
Multiple Airlines Logo
12:35 pm - 11:55 am
SLU
-
BOS
23h 20m
2 stops
$870Multiple Airlines
Mon, Nov 2 - Sat, Nov 7
Multiple Airlines Logo
5:30 am - 7:00 pm
BOS
-
SLU
12h 30m
2 stops
Multiple Airlines Logo
12:35 pm - 9:57 am
SLU
-
BOS
22h 22m
2 stops
$893Multiple Airlines
Thu, Nov 12 - Mon, Nov 16
Multiple Airlines Logo
5:30 am - 7:00 pm
BOS
-
SLU
12h 30m
2 stops
Multiple Airlines Logo
12:35 pm - 9:37 am
SLU
-
BOS
22h 02m
2 stops
$906Multiple Airlines
Thu, Nov 12 - Mon, Nov 16
Multiple Airlines Logo
5:30 am - 7:00 pm
BOS
-
SLU
12h 30m
2 stops
Multiple Airlines Logo
12:35 pm - 9:37 am
SLU
-
BOS
22h 02m
2 stops
$916Multiple Airlines
Mon, Nov 9 - Sun, Nov 15
Multiple Airlines Logo
5:30 am - 7:00 pm
BOS
-
SLU
12h 30m
2 stops
Multiple Airlines Logo
12:35 pm - 9:37 am
SLU
-
BOS
22h 02m
2 stops
$927Multiple Airlines
Sat, Jul 4 - Wed, Jul 8
Multiple Airlines Logo
7:15 pm - 7:00 pm
BOS
-
SLU
23h 45m
2 stops
Multiple Airlines Logo
12:35 pm - 9:53 am
SLU
-
BOS
21h 18m
2 stops
$940Multiple Airlines
Sat, Jul 4 - Sat, Jul 11
Multiple Airlines Logo
6:00 am - 7:00 pm
BOS
-
SLU
13h 00m
2 stops
Multiple Airlines Logo
12:35 pm - 9:53 am
SLU
-
BOS
21h 18m
2 stops
$942Multiple Airlines
Sat, Jul 4 - Sat, Jul 11
Multiple Airlines Logo
6:00 am - 7:00 pm
BOS
-
SLU
13h 00m
2 stops
Multiple Airlines Logo
12:35 pm - 9:53 am
SLU
-
BOS
21h 18m
2 stops
$946Multiple Airlines
Mon, Nov 23 - Sun, Nov 29
Multiple Airlines Logo
5:30 am - 7:00 pm
BOS
-
SLU
12h 30m
2 stops
Multiple Airlines Logo
12:35 pm - 9:37 am
SLU
-
BOS
22h 02m
2 stops
$953Multiple Airlines
Booking Insights

KAYAK's insights & trends for Boston to Castries flights

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

What is the cheapest month to fly from Boston to Castries?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Boston to Castries, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Boston to Castries is May, where tickets cost $0 (return) on average. On the other hand, the most expensive months are April and June, where the average cost of round-trip tickets is $1,030 and $832 respectively.

Find deals

Good to know

Low seasonAugust
Cheapest flight$404
Best time to beat the crowds with an average 41% drop in price.
Most popular time to fly and prices are also 9% lower on average.
Flight from Boston to Castries

When to book flights from Boston to Castries

Are your dates flexible? Find out the best times to travel from Boston to Castries 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 Boston to Castries

  • What is the cheapest flight from Boston to Castries?

    In the last 5 days, the lowest price for a flight from Boston to Castries was $404 for a one-way ticket and $869 for a round-trip.

  • Do I need a passport to fly between Boston and Castries?

    Yes

  • Which aircraft models fly most regularly from Boston to Castries?

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

  • How does KAYAK find such low prices on flights from Boston to Castries?

    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 Boston to Castries.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Boston to Castries?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Castries from Boston 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 Boston to Castries?

    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 Castries with an airline and back to Boston with another airline. Booking your flights between Boston and SLU 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 Boston to Castries?

    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 Castries from Boston 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 Boston to Castries

 
See real verified KAYAK customer reviews for airlines flying from Boston to Castries. 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 Boston to Castries? 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.
7.1
JetBlueOverall score based on 2996 reviews
7.2Entertainment
7.3Boarding
6.6Food
7.5Comfort
7.9Crew
Airline reviews

Domestic flights are good. Just stay away from international travel

8.0 ExcellentHugo, Jun 2026
JFK - BUF
Read more JetBlue reviews

Domestic flights are good. Just stay away from international travel

Flight left 2 hours late with no explanation as to the delay

The aircraft was fine, it’s was just the service. The flight got canceled several times and that was very inconvenient for my 69 years old mom.

My checked in luggage cost was $59, almost ticket price. The first 13 rows were empty, but fly attendant did not alow women with little boy change her middle sit, sweet boy was crying, I am so sorry for mother and passengers. At the end of the flight the cabin became impossible cold. Only good was timing of departure and early landing, but it suppose to be normal.

Seamless flight, didn’t feel like five hours at all very smooth ride. Watched two good movies didn’t even realize I was on a plane. The staff were extremely nice and helpful.

I tried to book a flight with Jet Blue. Your third party company hijacked my attempt with a website that looked like I was booking with Jet Blue. I realized it when I paid. I tried to cancel and was told by a man in India that there were no refunds. $735 stolen, Thanks Kayak!

It was inexplicably canceled and we are stuck in LA, haven't gotten home and it has been an inconvenience having lost work (on unpaid leave for my husband).

I like everything. Blythe at DCA is the absolute best!

JetBlue worker, Blythe, was so amazing at the DCA counter. If it wasn’t for her, I’m not sure we would’ve made it through. Please thank her!

They lost my luggage and refuse to help. Terrible airline. I've never experienced worse customer service in my life. Pretty much just told me too bad that I lost all my luggage, not caring that I am stuck in Europe for 2 weeks with absolutely nothing.

Everything you need to know for your flight from Boston to Castries

Information on your arrival and departure airports

Boston (BOS)
Castries (SLU)