Sometimes. Citizens of the UK, Australia, New Zealand, most EU countries, Canada and the United States do not require a visa to visit Thailand for up to 30 days. If entering Thailand by land border then they will usually only be granted a visa valid for 15 days.
EU citizens and other nationals not listed above should check with the Thai Embassy in their country of residence for the most up-to-date information.
In the event of a visa being required (see above), arrangements should be made with the Thai Embassy in the advance of your departure to Thailand. It is usually a single entry visa that allows you to travel in the country for 30 days. Many embassies offer an express service as well as a multiple entry visa, both at additional cost.
You will need one clear page (per visa) in a full passport that is valid for at least 6 months beyond the date of your departure from Thailand.
Proof on onward travel is required if flying into Thailand on a one-way flight (i.e. without an exit flight from Thailand). If proof is requested, your Selective Asia itinerary is sufficient proof of your onward travel arrangements.
All foreign nationals entering Thailand must complete a digital arrival card online before arrival. You can register for an arrival card within 3 days of your arrival - please visit https://tdac.immigration.go.th/arrival-card
.