Smoking: banned on many beaches and in most public indoor spaces

Thailand has strict tobacco-control rules that catch tourists who assume the beach is a free-for-all. Since 2017 smoking has been banned on a list of popular public beaches under a Department of Marine and Coastal Resources order, with fines up to 100,000 baht or up to a year's imprisonment for serious cases — in practice you are moved on or fined, and designated smoking zones are provided at some beaches. Under the Non-Smokers' Health Protection Act B.E. 2560 (2017), smoking is prohibited in most enclosed public places and workplaces — airports, malls, markets, restaurants (including many open-air ones), public transport and government buildings — with fines for offenders and larger fines for venue owners who allow it.

A lesser-known rule that has caught residents: since 2019 smoking inside your own home can be treated as domestic violence if the smoke harms family members' health. Ordinary cigarettes are legal to buy and sold widely, but you must have a passport-age face for the 20-plus age limit and stick to permitted areas. Vaping, as covered separately, is a different and far more serious matter — it is banned outright.