The purpose of this article is to explore recent research into World Englishes (henceforth WEs) and English as a Lingua Franca (ELF),1 focusing on its implications for TESOL, and the extent to which it is being taken into account by English language teachers, linguists, and second language acquisition researchers. After a brief introduction comparing the current situation with that of 15 years ago, I look more closely at definitions of WEs and ELF. Then follows an overview of relevant developments in WEs and ELF research during the past 15 years, along with a more detailed discussion of some key research projects and any controversies they have aroused. I then address the implications of WEs/ELF research for TESOL vis-à-vis English language standards and standard English, and the longstanding native versus nonnative teacher debate. Finally, I assess the consensus on WEs and ELF that is emerging both among researchers and between researchers and language teaching professionals. The article concludes by raising a number of questions that remain to be investigated in future research.