A firearm license in Thailand is granted only for self-defense, property protection, hunting, or sporting use. A license may not be issued to anyone who is a repeat offender or mentally unstable. Citizenship is not required to purchase and use firearms. But non-citizens must have a resident permit. A person is also not allowed to carry their gun without an additional permit for concealed carry. Even for Thai citizens permitted to own firearms, firearms are expensive. Fully automatic firearms and explosive devices are prohibited.

What's the best answer to this question: is it legal to own a gun in thailand?
yes