Social inclusion policy in Australia has largely ignored key issues of communication for linguistic minorities, across communities and with the mainstream community. In the (now disbanded) Social Inclusion Board's reports (e.g., Social Inclusion Unit, 2009), the emphasis is on the economic aspects of inclusion, while little attention has been paid to questions of language and culture. Assimilatory aspects of policy are foregrounded, and language is mainly mentioned in relation to the provision of classes in English as a Second Language. There is some recognition of linguistic diversity but the implications of this for inclusion and intercultural communication are not developed. Australian society can now be characterised as super-diverse, containing numerous ethnic groups each with multiple and different affiliations. We argue that a social inclusion policy that supports such linguistic and cultural diversity needs an evidence-based approach to the role of language and we evaluate existing policy approaches to linguistic and cultural diversity in Australia to assess whether inclusion is construed primarily in terms of enhancing intercultural communication, or of assimilation to the mainstream.