$639 Cheap Flights from Boston (BOS) to Sion (SIR)

View $639 flight on Sat, Mar 14, 2026Opens in a new window

Popular airlines from Logan International Airport (BOS) to Sion (SIR)

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Cheap Flights from Boston to Sion (BOS-SIR)

Prices were available within the past 7 days and start at $639 for one-way flights and $1,794 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Sat, Mar 14 - Sat, Mar 21
BOS
Boston
SIR
Sion
$1,794 Roundtrip, found 18 hours ago
$1,794
Roundtrip
found 18 hours ago
Select United flight, departing Sat, Mar 14 from Boston to Sion, returning Sat, Mar 21, priced at $1,794 found 18 hours ago
United
Sat, Mar 14 - Sat, Mar 21
BOS
Boston
SIR
Sion
$1,869 Roundtrip, found 18 hours ago
$1,869
Roundtrip
found 18 hours ago
Select United flight, departing Sat, Mar 14 from Boston to Sion, returning Sat, Mar 21, priced at $1,869 found 18 hours ago
United
Sat, Mar 14 - Sat, Mar 21
BOS
Boston
SIR
Sion
$3,571 Roundtrip, found 18 hours ago
$3,571
Roundtrip
found 18 hours ago
Select United flight, departing Sat, Mar 14 from Boston to Sion, returning Sat, Mar 21, priced at $3,571 found 18 hours ago
United
Sat, Mar 14 - Sat, Mar 21
BOS
Boston
SIR
Sion
$3,654 Roundtrip, found 18 hours ago
$3,654
Roundtrip
found 18 hours ago
Select United flight, departing Sat, Mar 14 from Boston to Sion, returning Sat, Mar 21, priced at $3,654 found 18 hours ago
United
Sat, Mar 14 - Sat, Mar 21
BOS
Boston
SIR
Sion
$4,848 Roundtrip, found 18 hours ago
$4,848
Roundtrip
found 18 hours ago
Select United flight, departing Sat, Mar 14 from Boston to Sion, returning Sat, Mar 21, priced at $4,848 found 18 hours ago
United
Sat, Mar 14 - Sat, Mar 21
BOS
Boston
SIR
Sion
$5,097 Roundtrip, found 18 hours ago
$5,097
Roundtrip
found 18 hours ago
Select United flight, departing Sat, Mar 14 from Boston to Sion, returning Sat, Mar 21, priced at $5,097 found 18 hours ago
United
Sat, Mar 14 - Sat, Mar 21
BOS
Boston
SIR
Sion
$5,381 Roundtrip, found 18 hours ago
$5,381
Roundtrip
found 18 hours ago
Select United flight, departing Sat, Mar 14 from Boston to Sion, returning Sat, Mar 21, priced at $5,381 found 18 hours ago
United
Sat, Mar 14 - Sat, Mar 21
BOS
Boston
SIR
Sion
$5,406 Roundtrip, found 18 hours ago
$5,406
Roundtrip
found 18 hours ago
Select United flight, departing Sat, Mar 14 from Boston to Sion, returning Sat, Mar 21, priced at $5,406 found 18 hours ago
United
Sat, Mar 14 - Sat, Mar 21
BOS
Boston
SIR
Sion
$5,606 Roundtrip, found 18 hours ago
$5,606
Roundtrip
found 18 hours ago
Select United flight, departing Sat, Mar 14 from Boston to Sion, returning Sat, Mar 21, priced at $5,606 found 18 hours ago
United
Sat, Mar 14 - Sat, Mar 21
BOS
Boston
SIR
Sion
$5,918 Roundtrip, found 18 hours ago
$5,918
Roundtrip
found 18 hours ago
Select United flight, departing Sat, Mar 14 from Boston to Sion, returning Sat, Mar 21, priced at $5,918 found 18 hours ago

Frequently asked questions

How much does a flight from Logan Intl. Airport (BOS) to Sion Airport (SIR) cost?
Secure a cheap one-way flight from $639 or cheap return flight from $1,794 from Logan Intl. Airport (BOS) to Sion Airport (SIR) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to see our cheapest flight offers on this route.
What is the cheapest month to fly from Logan Intl. Airport (BOS) to Sion Airport (SIR)?
March is the cheapest month to fly from BOS to SIR. Timing your trip outside of the busy season is often the key to finding better fares.
What is the cheapest airline that flies from Logan Intl. Airport (BOS) to Sion Airport (SIR)?
To find the cheapest airline flying from BOS to SIR, use Expedia's filter tool. Customize your search based on what's important to you, such as preferred carriers and flight duration. You can then sort your results by "Price (lowest to highest)" to see the most affordable options first.
How many flights per day from Logan Intl. Airport (BOS) to Sion Airport (SIR)?
You'll need to book a flight with a layover if you're traveling from Logan Intl. Airport (BOS) to Sion Airport (SIR). Direct flights don't operate daily on this route. However, simply filter your search to include one or more stops to discover an option that works for you.
What day of the week has the most flights from BOS to SIR?
Friday is generally the busiest day for flights, while Tuesday is often the quietest.* Keep in mind that flight schedules can change based on various factors, including the time of year and airline.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Logan Intl. Airport (BOS) to Sion Airport (SIR)?
To touch down at Sion Airport (SIR) on time, book a flight that leaves from Logan Intl. Airport (BOS) before 3 PM. The chance of cancellations is 22% higher, on average, for departures after this time.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from Logan Intl. Airport (BOS) to Sion Airport (SIR) last-minute?
Holding off until just before your departure to book a flight from BOS to SIR often results in higher prices. While you may come across some last-minute discounts, they're not always guaranteed. Be flexible with your itinerary to boost your chances of getting a bargain.
Is it cheaper to book a BOS to SIR flight and hotel package?
Securing a BOS to SIR flight and hotel package tends to be cheaper than booking separately. With Expedia, you can enjoy the convenience of organizing your travels all in one place. Select from our wide range of stays and then add flights, car rentals and activities to your booking. Bundle it all together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Logan Intl. Airport (BOS) to Sion Airport (SIR)?
Typically, it's possible to cancel or reschedule your BOS to SIR flight. However, if it's been more than 24 hours since booking, additional fees may apply. Refer to your airline's policies in your itinerary to see what changes are possible and whether any costs are involved. You'll also find more details on our Customer Service portal.

Travel information

Origin airport
Logan Intl.
Destination airport
Sion
Roundtrip price
$1,794
Distance
3721 mi

Book with confidence

Boston to Sion Flights

The cheapest times to fly from Boston to Sion

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Boston to Sion are during the month of March. You can find some of the cheapest flights from Boston to Sion with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Boston to Sion

Sunday is one of the best days to book for cheap flights from Boston to Sion: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Boston to Sion

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Boston to Sion in 2025. You can also book with separate airlines for your outbound and return journeys, from $639 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Boston to Sion flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Boston to Sion airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Boston to Sion Flights

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*Available to One Key members.