BOS - SLU

$443 Find Cheap Flights from Boston to Castries

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 9/4. 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

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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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

Thu, Oct 9 - Mon, Oct 13
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9:55 am - 11:30 amBOS-SLU
25h 35m3 stops
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12:35 pm - 2:30 pmSLU-BOS
25h 55m3 stops
$1,003
Find Deal
Thu, Oct 9 - Mon, Oct 13
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6:00 am - 7:00 pmBOS-SLU
13h 00m2 stops
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9:10 am - 9:55 amSLU-BOS
24h 45m2 stops
$1,069
Find Deal
Thu, Oct 2 - Sun, Oct 5
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10:00 am - 11:30 amBOS-SLU
25h 30m3 stops
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5:00 am - 6:10 pmSLU-BOS
13h 10m2 stops
$1,303
Find Deal
Thu, Oct 2 - Sun, Oct 5
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6:10 am - 11:30 amBOS-SLU
29h 20m2 stops
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5:00 am - 6:10 pmSLU-BOS
13h 10m2 stops
$1,379
Find Deal
Tue, Nov 25 - Sun, Nov 30
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10:45 am - 9:30 amBOS-SLU
21h 45m2 stops
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12:10 pm - 9:32 amSLU-BOS
22h 22m2 stops
$1,448
Find Deal
Fri, Sep 12 - Fri, Sep 19
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4:45 pm - 1:10 pmBOS-SLU
20h 25m2 stops
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12:15 pm - 9:55 amSLU-BOS
21h 40m2 stops
$1,522
Find Deal
Wed, Nov 26 - Sun, Nov 30
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6:40 pm - 5:35 pmBOS-SLU
21h 55m2 stops
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12:10 pm - 9:32 amSLU-BOS
22h 22m2 stops
$1,746
Find Deal
Sat, Jan 31 - Sat, Feb 7
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5:30 am - 11:25 amBOS-SLU
28h 55m2 stops
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6:20 pm - 12:14 pmSLU-BOS
18h 54m2 stops
$2,151
Find Deal
Thu, Nov 13 - Mon, Nov 17
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6:15 am - 11:30 amBOS-SLU
28h 15m3 stops
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4:35 pm - 9:52 amSLU-BOS
42h 17m2 stops
$2,558
Find Deal
Thu, Nov 6 - Sun, Nov 9
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6:15 am - 11:30 amBOS-SLU
28h 15m2 stops
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12:30 pm - 12:12 pmSLU-BOS
48h 42m3 stops
$2,584
Find Deal
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.

How much is a round-trip flight from Boston to Castries?

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 March, where tickets cost $537 (return) on average. On the other hand, the most expensive months are July and August, where the average cost of round-trip tickets is $867 and $835 respectively.

Good to know

Low seasonAugust
Cheapest flight$443
Best time to beat the crowds but there is an average 24% increase in price.
Most popular time to fly and prices are also 1% 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 3 days, the lowest price for a flight from Boston to Castries was $443 for a one-way ticket and $1,003 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.

  • Which is the best airline for flights from Boston to Castries, JetBlue or American Airlines?

    The two airlines most popular with KAYAK users for flights from Boston to Castries are JetBlue and American Airlines. With an average price for the route of $670 and an overall rating of 7.2, JetBlue is the most popular choice. American Airlines is also a great choice for the route, with an average price of $603 and an overall rating of 7.2.

  • 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 airlines 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.
7.2
American AirlinesOverall score based on 10000 reviews
7.2Comfort
8.0Crew
6.9Entertainment
7.5Boarding
6.5Food
Airline reviews

The flight was canceled 3 hours after original take off time

2.0 MediocreAnonymous, Aug 2025PHL - LHR
Read more American Airlines reviews

The flight was canceled 3 hours after original take off time

My flight was delayed for several hours. Sitting at gate 16 for several hours, I got a text from Kayak the gate changed to 9 before it was announced. Very bad communication at each gate from American Airlines employees. I received 10 notifications of delay from Kayak. My vacation started off horrible! I will write to American Airlines corporate office also.

The AA staff person who checked our bags was curt and almost rude. The FA also seemed unhappy doing her job. Overall it was like riding the school bus back in grade school.

Internet was a bit expensive and did not work ask that week otherwise a good flight

Ring in first class for an overnight flight, there was no blankets nor pillows for first class customers.

My Internet did not work for Outlook email or basically anything. I paid for one hour of in-flight usage and it was terrible. I spent a lot of time on different sites and browsers with no luck and a lot of frustration. Other than that, the flight was on time, crew was nice, service was fine. Seat was OK even though I paid for the extra 6 inches. I cannot imagine how tight the seats in the back must be.

Delayed flight that lead to a missed connection and a 5-hour trip became a 12-hour flight 🙄

Any flight to ORD after about 2pm this summer has been challenging. Flight was delayed getting in (coming from ORD) and that led to it not leaving before a ground stop due to lightening before they could fuel the plane, and so forth. They made up some time but we were still late in arriving at ORD, and that led to missed connections.

Food was ok, but not as good as I have had before on AA.

No issues. They did change our gate FOUR times in about 30 minutes which was mildly annoying but the flight was fine.

I paid extra for a seat closer to the front. The TV didn’t work at all for the entire flight. Would have been nice to know before I purchased an “upgraded “ seat

It was great. I had never flown on JetBlue before, but would be very happy to fly with them in the future.

Worst flight experience ever flights canceled. JetBlue told us just did not even bother standing in line to come back in one and a half hours then without any information we had to go pick up all of our luggage and spend over $2000 in accommodation just to get home. JetBlue said that the next flight available for us to get home would be three days later. Absolutely absurd hasn’t offered to give us any compensation do not fly JetBlue horrible company. They said it was based on the weather and the weather is great in all locations that we would’ve been flying to total hoax. I think it’s a conspiracy theory.

The captain gave good announcements and the flight attendants were friendly. The WiFi was pretty good. The plane itself looked very old inside and the seats were very uncomfortable. The screens in the seat backs were the smallest I’ve ever seen. There were so many loud and obnoxious kids on this flight and the parents didn’t do much to try to quiet them down. Some had videos and games on tablets with higher than necessary volume going the whole time.

Too many long delays with JetBlue. Worst major airline that serves JFK but unfortunately I keep going back because of the prices.

My JetBlue experience was nice. The flights ran on time, the aircraft was clean and comfortable, and the flight attendants were attentive. My only issue, which is isolated to the low-cost (budget) option at JetBlue, is that the check in process makes the user feel that they have to buy their seats. The seats offered for purchase are upgrades from the budget seats you get (which are essentially the last seats remaining). The interface should not make it feel like you must purchase a seat.

The plane was late to leave.. Internet was lousy. TV was not working. when we arrived, We stayed on the plane for a long time before we got to the gate. It took us a long time to retrieve our luggage because they didn’t know what carousel to send them to. It was a bad experience.

I especially liked the lead crew officer. His boarding and safety announcements were made with a bit of novelty and humor. The flight also left the gate 10 minutes early and we landed about 20 minutes early… It was a delightful flight…

There were mutliple delays. There was inconsistent, delayed, and poor communication regarding the delays.

flight was delayed for hours with no explanation. The plane was a very old aircraft.

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

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