Play behaviour in the juvenile South American fur seal (Arctocephalus australis) is described for the period of dependence on the mother (up to 32 months). Play does not appear to be a unitary category of behaviour, but may be separated into four distinct types: terrestrial social and solitary play and swimming social and solitary play. These four types show different development profiles, and appear to serve different functions. Terrestrial solitary play and the two swimming play forms appear to be juvenile specializations, the first to enable very young seals to gain motor skills rapidly in order to avoid dangers from conspecifics, the second two to enhance antipredator behaviour and foraging ability during the gradual transition to independence. In contrast, social play may be best thought of as gaining social skills necessary in adult life, prior to dispersal post-weaning. Juvenile fur seals which do not wean in their first year show an upsurge in social play which is not seen in the other play types. This upsurge coincides temporally with the peak of social play of the new cohort, and is presumably elicited by them.