The Karen are one of the largest ethnic minority groups living in Thailand today, residing mostly in the mountainous ranges along the Thai-Burmese border. In most previous Karen studies, map presentation of Karen settlements has been disregarded. This paper explores the Karen from the spatial aspect. The study area covered 15 provinces in western and northern Thailand along the Thai-Burmese border. The scope of the study focused on the village locations of 6 Karen subgroups, namely the Sgaw, the Pwo, the Taungthu or Pa’O, the Kayah, the Kayan, and the Kayaw. A survey of these Karen subgroups settlements was performed via a questionnaire that was collected between 2011 and 2012. A spatial-based technique, the Geographic Information System (GIS), was used as a tool to develop a geographical database of Karen settlements. Further analysis was performed to explore the population numbers of Karen subgroups and their population change, settlement distribution, village size and the relationship of village locations to topography. The findings show that the Sgaw Karen are still the largest Karen-speaking group living in Thailand today. The population size of Karen villages varies largely but their average size is almost the same. According to the settlement pattern, Karen villages of the same subgroup tend to stay close together. A mixture of Karen subgroups in a village are found in small numbers. All subgroups are located on mountain peaks or at high elevations along the Thai-Burmese border or along the provincial boundaries. However, the Sgaw and the Pwo Karen tend to settle at a higher elevation than the Kayah and the Taungthu (Pa’O) Karen. The findings also suggest that the role of GIS is obvious, showing its great potential for advancing our understanding of Karen studies from the spatial aspect.