The goal of the present study was to devise a means of representing languages in a perceptual similarity space based on their overall sound structures. In Experiment 1, native English listeners performed a free classification task in which they grouped 17 diverse languages based on their sound similarity. A similarity matrix of the grouping patterns was then submitted to clustering and multidimensional scaling analyses. In Experiment 2, an independent group of native English listeners sorted the group of 17 languages in terms of their distance from English. Taken together, the results of the two experiments provide the basis for developing predictions regarding foreign-accented speech intelligibility.