Second language (L2) learning in the 21st century, perhaps more than in the last, will see shifting perspectives, priorities and tendencies. Whereas the late 20th century saw the rise to pre-eminence of English as the international language of communication, the decades to come may chronicle a challenge to that dominance as other world languages, such as Chinese and Spanish, jostle for supremacy. New technologies may accelerate the injection of alternative ways of delivering a second language curriculum. The profile of the L2 learner, already a complex and diverse one, may undergo fundamental changes as new societal, cultural, political and professional demands are imposed on the individual. Within all these developments the concept of the autonomous language learner may also shift, indeed it is shifting already. Yet it would seem important to safeguard a number of constants, particularly those regarding the right of self-determination of the individual. With this in mind, this paper elaborates on a model of autonomy first proposed in Macaro (1997). The model proposed 3 dimensions of L2 autonomy: autonomy of language competence; autonomy of language learning competence; autonomy of learner choice. In returning to this theme more than ten years later, the author still has in mind an L2 learner who is young and not that far advanced on his or her L2 learning path. This is not only because his professional experience lies with this group of learners but also because this group is still under-represented, perhaps even disenfranchised, in the second language acquisition and L2 pedagogy literature. Each of these dimensions will be examined and then brought together in the concluding remarks.