Thailand is the land of smiles and delicious food, even for the gluten free traveler! Almost all the curries I encountered were gluten free and dairy free, making it another one of the easiest GF countries to travel in. Nut allergies will be difficult in Thailand however, so be careful. Also be aware the spice level of most food in Thailand is not for the faint of heart.
Fried rice with egg, meat and veggies is a good option for breakfast or alternately the Thai desert ‘mango sticky rice’, which is not spicy at all and very delicious and simple, with fresh mango and coconut milk over sticky rice.
Fresh fruit is widely available everywhere as well, which is great for a snack or a light breakfast. In big cities like Bangkok, it is easy to find western style breakfasts in popular tourist areas, and popular brands of chips and chocolate bars.
The popular ‘pad thai’ rice dish was usually gluten free, but be aware that soy sauce can sometimes be used. It’s best to avoid anything deep fried, which includes tofu in case other non-GF things have been fried in the same oil and any brown colored sauces.
Gluten free (or other allergy) language cards are a big help to get your message across.
Enjoy the amazing cuisine of Thailand and safe travels!