There are people who believe that Thai people came from the island of Java, in Indonesia. This theory is unique when compared to the others, because all of the other theories say that Tai people came from north of modern day Thailand.

The person who put forth this theory (the person who made it up) was Dr. Somsak Phansonboon. He has studied blood types of Thai people and has noted that they are similar to those of people from the Malay Archipelago (the group of island around Malaysia and Indonesia). He also noted that there are similarities in the genes of Thai people and Indonesians.

The main problem with this theory is that there is no archeological evidence to support it. Linguists have also noted that there are no similarities between the languages which are spoken in Indonesia and the Thai language. This theory, therefore, is not one that is supported by many historians.