Previous language attitude research indicates that presenting speech forms allows listeners to index information about and attach social meaning to the perceived group(s) of speakers. Despite the volume of research undertaken elsewhere in Asia, there appear to be no in-depth studies investigating Thai nationals' evaluations of specific varieties of English speech. This large-scale study examines 204 Thai university students' attitudes towards forms of UK, US, Japanese, Chinese, Thai and Indian English, provided by highly proficient female speakers. The study also examines the extent to which Thai students' perceptions of linguistic diversity in their L1 and their gender affect their attitudes. Multivariate analysis demonstrated UK, US and Thai English speech was ranked significantly higher than other Asian forms of English, for competence and warmth, attitudinal dimensions consistent with recent findings in social cognition. Further analysis indicated females and those most positive towards L1 variation expressed significantly higher levels of ingroup loyalty towards Thai English speakers. The findings are compared and contrasted with the results of equivalent studies undertaken in other Asian contexts and, given recent cutting-edge research in social cognition confirming the primacy of warmth judgements, calls for language attitude researchers to consider speaker warmth ratings more fully in future studies.