This study empirically examined the antecedents of market orientation, how competitive strategy affects the relationship between market orientation and business performance, and the relationship between market orientation and business performance, using Korean overseas subsidiaries operating in the North American market as the research sample. The research results identified firm size and market turbulence as explanatory variables enabling market orientation. Specifically, market orientation was found to be higher as firm size increases and as market turbulence increases. Furthermore, when examining the role of competitive strategy as a moderating variable affecting the relationship between market orientation and business performance, it was found that the greater the cost competitive advantage, the greater the effect of market orientation on quantitative performance, namely growth (sales growth rate), while conversely, the greater the differentiation, the greater the effect of market orientation on qualitative performance, namely profitability (net income growth rate). Finally, higher market orientation was found to lead to improved business performance.