The influence of individual difference variables on second language (L2) listening comprehension has been an area of research that has been gaining renewed attention in recent years. The current study investigated the effects of two cognitive variables, aptitude and metacognitive awareness, on 107 native-Korean, English as a foreign language learners' listening comprehension. Moreover, the study examined whether metacognitive awareness mediated the relationship between aptitude and L2 listening comprehension. Both aptitude and metacognitive awareness were found to have statistically significant positive correlations (r = 0.58 and 0.37, respectively) with L2 listening comprehension, and they were also significant predictors of L2 listening, collectively explaining 41% of the variance in L2 listening performance. Furthermore, metacognitive awareness mediated the relationship between aptitude and L2 listening comprehension. These findings suggest that cognitive learner variables play a significant and interdependent role in L2 listening comprehension.