The Charter of the Association of Southeast Asian Nations (ASEAN) was officially adopted in February 2009. Article 34 of the Charter states that, 'The working language of ASEAN shall be English'. In this article, I first briefly trace the development of English in ASEAN and demonstrate that, even in those countries of the ASEAN group which were not colonies of Britain or the United States, English has become increasingly important. I show that, in almost all the cases, the language policies of ASEAN countries require people to learn their respective national language and English. This combination of the learning of English is along with the learning of a national language, which can be a national lingua franca such as Bahasa Indonesia in Indonesia and Filipino in the Philippines. Consequently, local and indigenous languages, other than the national language, are being replaced by English in many school curricula and also in other domains. It is also rare to find government schools in ASEAN teaching the national languages of other ASEAN states. I conclude by considering the implications of this for multilingualism in the region.