This article provides a brief overview of the relationship between libertarian political theory and the Basic Income (BI). It distinguishes between different forms of libertarianism and argues that at least one form, classical liberalism, is compatible with and provides some grounds of support for BI. A classical liberal BI, however, is likely to be much smaller than the sort of BI defended by those on the political left. And there are both contingent-empirical and principled-moral reasons for doubting that the classical liberal case for BI will be ultimately successful.