The purpose of this chapter is to explore how the teaching of the History of the English Language (HEL) can support English Language Teaching (ELT) in Japan. The chapter proposes that perspectives from the study of HEL can enrich learners’ comprehension of Present-Day English. From a language-internal perspective, it highlights features such as the pronunciation-spelling correspondences, the multi-layered vocabulary, and the varying patterns of English grammar. From a language-external perspective, this chapter argues that HEL can foster learners’ awareness of the diverse varieties of English and challenge the idea that there is a single, correct form of English. Although both the theory and practice of HEL pedagogy have received extensive coverage in English-speaking contexts, it seems that very little has been reported internationally about either the state or importance of HEL teaching in Japan. This chapter thus examines the role of HEL pedagogy in Japan and considers what broader implications it may have for ELT. Finally, it argues that HEL should be presented not merely as a historical subject but as one closely connected to Present-Day English.