This article explores the implications of John Rawls' political liberalism for linguistic diversity and language policy, by focusing on the following question: what kind(s) of equality between speakers of different languages and with different linguistic identities should the state guarantee under political liberalism? The article makes three claims. First, language policy under political liberalism should guarantee the equal basic rights and liberties of all citizens, regardless of language(s) spoken. This may require positive forms of state intervention, such as the provision of interpreters and translators in courts of law or hospitals. Second, while permissible under political liberalism, symbolic recognition by the state of all languages is not required, because the notion of self-respect does not involve the ability to identify with the institutions of one's own political community. Finally, while neither the protection of citizens' basic rights and liberties, nor the guarantee of their self-respect, demands multilingual policies, the latter may be required under political liberalism by the principle of fair equality of opportunity. This last step involves recourse to democratic deliberation in order to ascertain people's linguistic identities, the costs they associate with the enjoyment of available opportunities and their resulting demands with regard to language policy.