This paper revisits and reanalyses data from a study carried out in the further education and training sector in the Republic of Ireland to investigate (1) how adults access and participate in numeracy courses and (2) how adult numeracy provision might support active citizenship. We analysed 45 interviews with adult education providers, adult numeracy tutors, and adult learners to identify themes that connect adult numeracy with a human rights conception of citizenship as access to and participation in economic, social, and community life. This analysis found that the most common barriers to accessing adult numeracy courses arose from dispositional factors relating to fear, anxiety and lack of confidence with mathematics, largely due to negative experiences in formal schooling. To overcome these barriers, adults' participation in numeracy courses was encouraged by integrating numeracy learning activities into real world contexts in a non-threatening learning environment. The interview analysis also illustrated ways in which adult numeracy education supported active citizenship in the economic, social, and community spheres, by (i) enhancing financial literacy and preparing adults for employment; (ii) fostering individual empowerment, family learning and social inclusion; and (iii) enabling civic engagement. Policies for promoting adult education typically aim to develop active citizenship, but without specifying how this is to be achieved. Our study is valuable because it illuminates potential connections between citizenship and numeracy as a dimension of adult education that is separate from literacy. The findings lead to recommendations for translating national and international policy frameworks into research-informed adult education programs.