This chapter first introduces the concept of competitiveness and identifies the factors that affect a company’s competitiveness from a holistic perspective. Subsequently, supply chain competitiveness is defined and the literature on factors affecting supply chain competitiveness is reviewed. The competitiveness of semiconductor manufacturing then comes into focus. Qualitative and quantitative methods for assessing the competitiveness of semiconductor manufacturers are introduced. To illustrate these assessment methods, the impact of recent fab localization initiatives on the competitiveness of these foundries is assessed. Based on the assessment results, the competitiveness of semiconductor manufacturers in various countries are compared. The second part of this chapter introduces the concept of sustainability. A company’s short-term competitiveness is often thought to contribute to its long-term sustainability. However, some recent cases have shown that it is possible to pursue long-term sustainability at the expense of short-term competitiveness, such as the recent supply chain localization initiatives of some foundries. Nonetheless, the chapter concludes with a discussion of how to enhance the competitiveness and sustainability of semiconductor manufacturing through localization of supply chains.