There exists a dearth of research investigating how listeners use their knowledge of variation in their L2 to categorise speaker provenance from stimulus speech. The present study, employing a free classification measure, examined 191 Thai university students’ categorisations of the geographical origin of nine speakers of English. Analysis demonstrated participants were generally able to distinguish between native and non-native English speech more broadly, and this distinction was found to be the primary perceptual dimension underlying speaker provenance categorisations. With regards to more fine-grained classifications, recognition rates for Thai, UK, US and Indian English speakers were substantially higher when compared to Vietnamese and Australian English speakers, indicating the social-psychological salience of the speech forms, rather than geographical proximity, was key in determining categorisation accuracy. Analysis of misidentification patterns showed a tendency for the Thai students to conflate Asian English speech forms, despite substantial phonological and phonetic differences between the English spoken in different Asian nations. Participant comments also indicated segmental features were largely responsible for (mis)categorisations. Consistent with speaker evaluation theories, the findings point to speaker categorisation as an initial processing stage, leading to the activation of stereotypes about and attitudes towards the speakers’ perceived social and ethnic group membership.