The group of emerging economies plays an increasingly important role in the world economy. However, there has been minimal research on the relationship between innovation and national competitiveness in these countries. This article aims to elucidate the relationship between innovation and national competitiveness in 19 emerging economies from 2005 to 2020. To address the endogeneity problem, we employ the generalized method of moments (GMM). The Porter diamond model served as the theoretical framework for national competitiveness. Unlike previous studies, we include some interaction variables in the research models to explore the role of innovation in enhancing competitiveness. The findings underscore the significance of innovation, revealing a positive relationship between innovation and national competitiveness in emerging economies. Additionally, other macroeconomic factors such as international trade, per capita income, government efficiency, infrastructure, and human capital positively influence national competitiveness. Furthermore, the interaction variables between innovation and human capital, international trade, and government effectiveness yield positive outcomes in fostering national competitiveness. Based on these findings, several policy implications are proposed to promote innovation and enhance competitiveness in emerging countries in the future.