In this study, the authors explore how academic resilience of Korean high school students has changed over time and which of the underlying factors that make up students’ socio-economic background, in particular, has played a critical role in changes of academic resilience using PISA 2006-2015 data. The results from analysis in an international perspective show that Korea has witnessed a sharp drop in the proportion of academically resilient students since 2006. Accordingly, although Korea has a higher proportion of academically resilient students than the OECD average at all times, the gap has decreased significantly over time. Analyzing the ratio of academically resilient students in a within-country perspective using only Korean data, however, the authors found that academic resilience of Korean students decreased until 2012 but showed a slight rebound in 2015. The recent rebound in academic resilience seems to be related to a series of educational policies geared toward bridging the educational gap and temporary improvement of income distribution in recent years. Meanwhile, the relationships between household income and academic resilience in both reading proficiency and mathematics performance, are very strong and have been increasingly enhanced in recent years. Contrary to expectations, however, the association between parental occupational status and academic resilience is relatively weak, and the association is found to have been weakening over time. Based on the findings, the authors concluded that in order to bridge the educational gap between classes by improving academic resilience, it is urgently needed to strengthen educational welfare to make the association between household income and academic resilience much looser than it is now.