If you own a drone or are thinking of getting one, it is now a requirement that it is registered before it flies in Thailand.
The registration can be made at police stations. You will need your identification, serial number of the drone and a photo of it. From what I have read there is no mention of a fee but that does not mean there is not one, and there is no mention of whether a foreigner can own and operate a drone or not.
This registration is to be expected as it is well known that drones can cause havoc in the skies, and there are the privacy concerns. Registration is one way to reduce the risks to flying and perhaps help mitigate privacy concerns. But not sure !
If you fail to register a drone you can be fined 100,000 Baht / 5 years jail.
19th October, 2017
In a further development I have just learned that you cannot fly a drone, registered or not, within 9km of an airport. One unlucky Thai has just been charged by police with doing just that and sharing the imagery on social media. He was denied bail.
4th June 2019
It has just been announced that the regulations on drone use in Thailand are being relaxed before the end of this year. How they will be relaxed we don't know but it is said that the regulations will be more inline with international rules. More to come.