Cheap flights from Seattle to Bangkok from $421 BFI, SEA → BKK, DMK
Boeing Field International Airport (BFI), Seattle-Tacoma International Airport (SEA) → Suvarnabhumi Airport (BKK), Don Mueang International Airport (DMK)
The cheapest return found recently is $814 with Hainan Airlines, 28 Nov – 26 Jan 2027, found 3 days ago. The cheapest one-way found recently is $421 with Hainan Airlines, 28 Nov, found 4 days ago.
- Cheapest one-way found recently
- $421, found 4 days ago
- Cheapest return found recently
- $814, 28 Nov to 26 Jan 2027
- Usual return price
- $823 to $1,154
- Cheapest month to fly
- November 2026, return fares from $814 found in the last 7 days
Return
The cheapest return fare on each of 3 departure dates is usually $823 to $1,154.
Cheapest return found recently
$814
28 Nov – 26 Jan 2027 · Hainan Airlines
Seattle-Tacoma International Airport (SEA) → Suvarnabhumi Airport (BKK)
Leaves 10:20 a.m. · Return leaves 1:05 a.m. · 44 h 30 min of travel, both ways together
out 1 stop, back 1 stop
found 3 days ago
Cheapest nonstop return
None seen yet.
Found recently, and the cheapest we hold
$814 28 Nov – 26 Jan 2027found 3 days agoSee prices for these dates
It is also the cheapest return we hold, of any age.
What have prices looked like?
Over 42 days, 24 Sept to 11 Nov, the cheapest return we saw each day was $606 to $985.
Those were the prices on those days, not today's.
Is this a good return price?
Compared with the cheapest return fare on each of 3 departure dates from 28 Nov to 21 Jan 2027, found by travelers' searches in the last 7 days (economy, the price the seller showed on Aviasales). The usual range is the middle half of those prices.
Could nearby dates be cheaper?
We hold no other 59-night return fares leaving within 3 days of 28 Nov to compare.
Every date we hold
17 fares on 3 departure dates
See the chart as a table
| Dates | From | Airline | Airports | Stops | Found | |
|---|---|---|---|---|---|---|
| 28 Nov – 26 Jan 2027 | $814 | Hainan Airlines | Seattle-Tacoma International Airport (SEA) → Suvarnabhumi Airport (BKK) | out 1 stop, back 1 stop | found 3 days ago | See prices for these dates |
| 16 Dec – 22 Dec | $1,476 | Alaska Airlines | Seattle-Tacoma International Airport (SEA) → Suvarnabhumi Airport (BKK) | out 2 stops, back 1 stop | found 4 days ago | See prices for these dates |
| 21 Jan 2027 – 11 Mar 2027 | $832 | Philippine Airlines | Seattle-Tacoma International Airport (SEA) → Suvarnabhumi Airport (BKK) | out 1 stop, back 1 stop | found 6 days ago | See prices for these dates |
Which month looks cheapest?
November 2026 is the cheapest month — from $814.
Airlines on the cheapest dates: Hainan Airlines, Alaska Airlines, Philippine Airlines.
One-way
The cheapest one-way fare on each of 3 departure dates is usually $385 to $427.
Cheapest one-way found recently
$421
28 Nov · Hainan Airlines
Seattle-Tacoma International Airport (SEA) → Suvarnabhumi Airport (BKK)
Leaves 10:20 a.m. · 22 h 15 min trip
stops unknown
found 4 days ago
Cheapest nonstop one-way
None seen yet.
Found recently, and the cheapest we hold
$421 28 Novfound 4 days agoOpen this trip
$348 10 Mar 2027found 7 days agoOpen this trip
What have prices looked like?
Over 32 days, 25 Sept to 11 Nov, the cheapest one-way we saw each day was $233 to $1,586.
Those were the prices on those days, not today's.
Is this a good one-way price?
Compared with the cheapest one-way fare on each of 3 departure dates from 28 Nov to 10 Mar 2027, found by travelers' searches in the last 7 days (economy, the price the seller showed on Aviasales). The usual range is the middle half of those prices.
Could nearby dates be cheaper?
No. We hold one-way fares on 1 other departure date within 3 days of 28 Nov, and it is not cheaper.
Every date we hold
5 fares on 3 departure dates
See the chart as a table
| Dates | From | Airline | Airports | Stops | Found | |
|---|---|---|---|---|---|---|
| 28 Nov | $421 | Hainan Airlines | Seattle-Tacoma International Airport (SEA) → Suvarnabhumi Airport (BKK) | stops unknown | found 4 days ago | Open this trip |
| 29 Nov | $433 | Singapore Airlines | Seattle-Tacoma International Airport (SEA) → Suvarnabhumi Airport (BKK) | 1 stop | found 4 days ago | Open this trip |
| 10 Mar 2027 | $348 | Singapore Airlines | Seattle-Tacoma International Airport (SEA) → Suvarnabhumi Airport (BKK) | 1 stop | found 7 days ago | Open this trip |
Which month looks cheapest?
March 2027 is the cheapest month — from $348.
Airlines on the cheapest dates: Singapore Airlines, Hainan Airlines.
Premium cabin fares from Seattle to Bangkok
We hold no premium economy, business or first-class fares for this route: we collect them for the busiest routes, and this one is not among them yet.
Today's prices for 28 Nov – 26 Jan 2027 in another cabin: Premium economy · Business · First
Today's prices for 28 Nov in another cabin: Premium economy · Business · First
How far ahead were prices cheapest for Seattle to Bangkok?
Return
Fares 90 to 179 days before departure were typically 12% lower than 14 to 29 days before departure.
From the cheapest return each day between 24 Sept and 11 Nov (42 days), grouped by how many days ahead the flight left; one adult in economy.
Each range covers different departure dates, so this compares typical fares, not the same trip priced twice.
Prices reflect recent searches — current fares may differ.
See these ranges as a table
| Booked ahead by | Typical fare | Cheapest day | Above the cheapest | Days of prices |
|---|---|---|---|---|
| 14–29 days | $814 | $743 | +13% | 17 |
| 30–59 days | $993 | $829 | +38% | 20 |
| 60–89 days | $985 | $832 | +37% | 21 |
| 90–179 days | $719 | $606 | Cheapest seen | 32 |
| 180+ days | $957 | $957 | +33% | 8 |
One-way
Not enough history yet: in 32 days of one-way prices, 25 Sept to 11 Nov, fewer than 3 booking ranges had prices on 7 days or more.
Could a nearby airport be cheaper?
A different airport at either end can change the fare — sometimes a lot.
Return
Everett → Bangkok
34 km from Seattle
$1,976
$1,162 more than flying from Seattle
28 Nov – 26 Jan 2027 · PAE → BKK · out 2 stops, back 1 stop
found 5 days ago
Cheapest recent price on each route — round trip, per traveler in Economy. Distances are in a straight line.
One-way
Victoria → Bangkok
119 km from Seattle
C$603 (US$423)
C$3 (US$2) more than flying from Seattle
14 Jan 2027 · YYJ → BKK · 2 stops
found 2 days ago
Cheapest recent price on each route — one way, per traveler in Economy. Distances are in a straight line.
Live price for these dates
The cheapest return found recently is for 28 Nov – 26 Jan 2027. A live search on this page shows what those dates cost now, for one adult in economy.
Questions about this trip
How much is a return flight from Seattle to Bangkok?
The cheapest return found recently is $814 with Hainan Airlines, 28 Nov to 26 Jan 2027, found 3 days ago. The cheapest return fare on each of 3 departure dates is usually $823 to $1,154.
How much is a one-way flight from Seattle to Bangkok?
The cheapest one-way found recently is $421 with Hainan Airlines, 28 Nov, found 4 days ago. The cheapest one-way we hold, of any age, is $348 with Singapore Airlines, 10 Mar 2027, found 7 days ago. The cheapest one-way fare on each of 3 departure dates is usually $385 to $427.
What is the cheapest month to fly from Seattle to Bangkok?
November 2026 is the cheapest month for a return, from $814, 28 Nov to 26 Jan 2027, found 3 days ago. March 2027 is the cheapest month for a one-way, from $348, 10 Mar 2027, found 7 days ago.
How far ahead should I book a flight from Seattle to Bangkok?
In 42 days of prices between 24 Sept and 11 Nov, return fares 90 to 179 days before departure were typically 12% lower than 14 to 29 days before departure.
Which airlines have the cheapest flights from Seattle to Bangkok?
Between 28 Nov and 21 Jan 2027, Hainan Airlines has the cheapest return on 1 of the 3 departure dates we hold, Alaska Airlines on 1 and Philippine Airlines on 1. Between 28 Nov and 10 Mar 2027, Singapore Airlines has the cheapest one-way on 2 of the 3 departure dates we hold, and Hainan Airlines on 1.
Prices are what travelers' searches on Aviasales found in the last 7 days, in US dollars: the price the seller showed on Aviasales; bags may cost extra. Fares change, so check today's price before you book. How our prices work