This study aims to investigate the relationship between metacognitive awareness and the use of reading strategies in L1 and L2 reading depending on the participants' L2 reading proficiency. A total of 167 Korean EFL university students participated in this study. They responded to questionnaires asking about their metacognitive reading strategies in their L1 and L2 reading for academic purposes. The findings showed that (a) there were positive relationship between L1 reading and L2 reading in terms of their use of metacognitive reading strategies, and (b) significant differences were found in the use of strategies in L1 vs. L2 reading in terms of L2 reading proficiency: L1 and L2 global strategy use in the high proficiency group, L1 and L2 support strategy use in the high, intermediate, and low proficiency groups, and overall L1 and L2 metacognitive reading strategy use in the intermediate proficiency group. There were no significant differences in L1 and L2 problem-solving strategy use in all three proficiency groups. The most influential factor in predicting overall use of L2 metacognitive reading strategies was found to be L1 global strategy use. Pedagogical implications for strategy-based reading instruction were suggested.