Ruiz Devesa started his political career as a economic policy advisor to Jonás Fernández Álvarez, a member of the European Parliament since 2014. Together they co-edited a book on Charlemagne and the European Union.[5]
In 2019, Ruiz Devesa was elected as an MEP, and worked in the Committee on Culture and Education and the Committee on Constitutional Affairs. In 2021 he was appointed as a member of the Parliament's delegation to the Conference on the Future of Europe.[6] In 2022, he was the parliament's rapporteur on a proposal for an overhaul of European election rules that would give all EU citizens aged 18 and older a greater role in choosing the Commission president, allow them to vote for pan-European MEPs and choose postal voting.[7]
^Fernández Álvarez, Jonás; Ruiz Devesa, Domenec, eds. (2021). Carlomagno en la Europa de hoy: contribuciones a las III Jornadas Carlomagno en Gijón. Investigación y debate. Madrid: Catarata. ISBN978-84-1352-198-5.
^Lagarde, Christine. Letter to Domenec Ruiz Devesa, “Letter from the ECB President on Monetary Policy”, November 25, 2022. https://www.ecb.europa.eu/pub/pdf/other/ecb.mepletter221125_Devesa~be9008d61e.en.pdf.