Smoking at Bangkok - Suvarnabhumi Airport (BKK)
Airport Rating

Note: Recent Feedback at this airport is contradicting the
official feedback.
Vaping, Heat not Burn and E-Cigs are also banned.
See here.
Before Security Smoking
Update from Anja, November 2022: Smoking is
tolerated around the bus stop for the S1 bus to Khaosan on the
liwest level.
Update from Anja, October 2022: On the ground
floor at entrance 8 (where the buses start) is a pedestrian way
over the road to the parking facility. Follow it across the road and
you find a smoking area on the right next to the entrance of the
parking lot.
Update from Gilbert, October 2022: Landside, smoking corner
exists on the very end of the curb near door 1 (on the other end of
the building near door 10). There are ashtrays, but this seems to be
a "tolerated" situation more than anything else (no "official"
signs). FWIW airport guard staff point paasengers there who wish to
smoke.
After Security Smoking
Domestic - A Gates
There are no smoking areas in the domestic
boarding area (A gates). Feedback from Vivienne B. on the 22nd
August 2018.
Concourse C :
As of 3rd February 2019 no smoking areas
inside airports. This applies throughout Thailand.
Concourse D:
As of 3rd February 2019 no smoking areas inside
airports. This applies throughout Thailand.
Concourse E :
As of 3rd February 2019 no smoking areas inside
airports. This applies throughout Thailand.
Concourse F :
As of 3rd February 2019 no smoking areas inside airports. This
applies throughout Thailand.
Concourse G (International) :
Update from Monica, 21st March 2023: At the moment the smoking
room at Miracle lounge is closed.
Update from John M, February 2023: 5/2/2023, large smoking room
located airside miracle lounge opposite G2 ,lounge free biz
class,oneworld ff,or 1500 baht entry fee
Update from Benson, February 2023: Smoking room airside
opposite G2 in miracle lounge,entrance fee for lounge 1500 baht,or
biz class ticket,or oneworld ff status,was in there 5/2/2023.
Update from Jasper J., January 2023: I wanna give an update for
Bangkok Suvarnabhumi (BKK) as of today, Jan 5th 2023, there is a
smoking room at Miracle Lounge near gate G2.

Update from Darren, Aug 2022: Smoking area at
the very end of the outside departures concourse - outside GATE/DOOR
entrance number 10.
Dont know about the other end of the concourse?
Further Information

Official Website
and an Unofficial website