A foreign citizen who wishes to enter the Kingdom of Thailand is required to obtain a visa from a Royal Thai Embassy or a Royal Thai Consulate-General. However, nationals of certain countries do not require a visa if they meet visa exemption requirements.
They are nationals of countries which are exempted from visa requirements when entering Thailand for tourism purposes. Such nationals will be permitted to stay in the Kingdom for a period of not exceeding 30 days.
For more information, kindly refer to
http://www.mfa.go.th/main/contents/files/services-20150120-100712-551809.pdf
For more information, kindly contact the respective Ministry of Foreign Affairs of the Kingdom of Thailand in your domicile country for the latest updates.