Syntactic priming studies in second language (L2) have contributed to understanding how L2 speakers' syntactic knowledge is represented and processed. However, little is known about social influences on L2 speakers' syntactic processing and learning. The present study investigated whether L2 speakers' syntactic priming is influenced by social factors, specifically different accents of English speakers and their familiarity with those accents. Korean L2 learners of English with intermediate proficiency were asked to describe pictures depicting ditransitive events after listening to sentences recorded by three English speakers with different accents: a standard-accented speaker (an American English speaker), and two speakers with non-standard accents (a Korean English speaker and an Indian English speaker). The results of the picture description task showed that syntactic priming effects in Korean L2 English speakers were significantly influenced by speaker accents and their familiarity with the accents. In addition, their priming patterns and interactions with these factors changed over time. These results suggest that syntactic priming in L2 speakers is socially mediated. We propose that priming effects in real language use can be better accounted for using a combination of cognitive and sociolinguistic models of syntactic priming and speech production.