Maritime trade played a key role in the social and economic transformations across the prehistoric – early historic periods in Southeast Asia. The first appearance of the toponym “Suvarṇabhūmi” and “Suvaṇṇabhūmi” in Indian records shows the participation of South Asia in maritime trade networks with Southeast Asia from at least the 3rd century BC onwards. This was followed by the Chinese who recorded their journey to India through the Thai-Malay Peninsula from the 1st century BC, and the first group of western merchants who recorded their experience of the Southeast Asian coastline in Greek in the 2nd century. Contents from these surviving records have been studied in detail by several scholars for about a century. However, there are still many inconsistencies that stem from the absence of primary evidence. This study reanalyzed primary evidence written in Sanskrit, Pali, Chinese, and Greek before the 7th century AD, using astronomy, geography, and etymology as the main lines of investigative interpretation. The data was then synthesized in an attempt to identify the locations of early states along the Southeast Asian coastline. The results from this study have been useful in geo-locating places dating the early historical period in Southeast Asia.