Previous studies in Western contexts have examined the relationships between various board characteristics and CSR, yet the relationships need to be re-examined in non-Western contexts given differential theoretical premises across contexts. We specifically propose that the effects of board characteristics on CSR in Korea should be patterned distinctively from Western-based existing literature, focusing on three important board characteristics, such as a board’s independence, social ties, and diversity. Using a panel dataset from large Korean firms, we found that various relationships between board characteristics and CSR were non-linear, whereas most of the previous research on Western contexts found that the same relationships were linear. Specifically, curvilinear relationships were found between CSR and board independence (i.e., exponentially growing shape), CEO-outside director social ties (i.e., inverted U-shape), and educational diversity (i.e., U-shape). Our findings suggest that there is no universal feature of CSR-supportive board characteristics due to the unique characteristics of various institutional contexts.