Here is a video where I go over some of the best meditation retreat options foreigners coming to Thailand have. These are all places I know about personally, and have experienced on some level. There are a couple of more meditation retreats located in Chiang Mai, and one in Koh Lanta, one on Koh Phangan I think too – but I don’t know anything about them.
Enjoy the video – I hope you choose one of these places to do your Thailand meditation retreat.