This volume accentuates how ELT materials can be a mediation of capitalizing on moral and cultural values, which are more locally-grounded in respective Southeast Asia (SEA) countries. It features critical studies on locally-produced ELT materials (textbooks) situated in the following SEA countries: Timor-Leste, The Philippines, Singapore, Malaysia, Cambodia, Vietnam, Indonesia, and Thailand. The chapters, written by experts who know the ELT context of their respective SEA country, critically examine the design and use of ELT materials widely used in local and national contexts. Thus, the volume provides fresh insight into how values are uniquely manifested in language classroom materials. The present text also brings together empirical, conceptual and practical grounds for incorporating moral and cultural values into ELT materials development in such a way that it views morality and culture as a mutually complementing entity. This much-needed volume will be a valuable resource for those interested in the design and use of language materials in culturally and linguistically diverse contexts, such as in the Asia Pacific, America, Africa, and Europe.