I sometimes get asked about places to do theological studies in English here in Thailand but unfortunately there are not many options... largely because most people in Thailand don't speak much English. Most Bible colleges and seminaries in Thailand offer instruction in the Thai language only.
However, the following schools offer English-language theological studies courses within Thailand, mostly on a modular basis (i.e. instructors fly in for one to two week intensive courses in Bangkok, Chiang Mai, or some other large city)
Asia Baptist Graduate Theological Seminary - Th.M and Th.D
Asia Graduate School of Theology Alliance - MA, M.Th, Ph.D, some of which have course offerings in Thailand. Other courses are in other nearby Asian countries
Asia Biblical Theological Seminary - MA in Religious Education, and MA in Bible, Theology, & Ministry. This school is associated with Cornerstone University in Grand Rapids, Michigan, USA.
Biola University - Cook School of International Studies - Chiang Mai Extension - MA in Intercultural Studies, D.Miss, and Ph.D in Intercultural Studies or Intercultural Education. The entire MA and D.Miss programs can be completed in Chiang Mai, but only half of the Ph.D can be completed there. The other half must be done through summer intensives at Biola's campus in La Mirada, California, USA.
Fuller Theological Seminary - Chiang Mai Extension Program - D.Min in Ministry and Leadership in Asian Contexts
Bangkok Theological Institute - This is an extension program of the Asia Pacific Theological Seminary in Baguio, Philippines. This is an English language Assemblies of God school with an extension campus in Hua Mak, Bang Kapi, Bangkok. They offer one masters level class per quarter, taught by APTS or Assemblies of God Theological Seminary teachers. For information on the classes in Bangkok, contact Leely Lee at +66 (0) 2732-3553.
Distance Education Degree Programs
If you are interested in doing formal theological studies while living in Thailand, please check the websites above for more information. Other than these, you need to have Thai language ability or look into doing distance education courses online in English, such as those offered by Reformed Theological Seminary, Gordon-Conwell Theological Seminary, or Third Millennium Ministries/Birmingham Theological Seminary (free for non-U.S. residents).