Korean has two sibilant fricatives, /sh/ and /s*/, that are phonologically contrastive in the Seoul dialect but are widely believed to be phonetically neutralized in the Gyeongsang dialects spoken in southeastern South Korea, with both fricatives being acoustically realized as [sh]. The current study investigated the degree to which the perception of these fricatives by Seoul listeners is affected by knowledge of the speaker’s dialect. In the first task, the stimuli were two fricative-initial minimal pairs (i.e., four words) produced by 20 speakers each from Seoul and Gyeongsang. Half of the 18 listeners were told that the speakers were from Seoul, and the other half were told they were from Gyeongsang. Listeners identified the 160 word-initial fricatives and provided a goodness rating for each. It was found that neither the speaker’s actual dialect nor the primed dialect had a significant effect on either identification accuracy or listeners’ goodness ratings. In a second task, listeners identified tokens from a seven-step continuum from [sada] to [s*ada]. It was found that listeners who were primed for Gyeongsang dialect were more likely to perceive tokens as /s*/ than listeners primed for Seoul, which may reflect a dialect-based hypercorrective perceptual bias.