Studying the behaviour and positions of legislators and political parties in the European Parliament is one of the major strands of research on legislative politics in the European Union. While many valuable data collection efforts exist to this end, they are often limited in scope, unavailable for reuse by other researchers, or cannot easily be linked to other required data. In this paper, I introduce EuroParlBase, an automated, linked database of annotated European Parliament data, covering a period of over 25 years from 1999 to today. At its core, EuroParlBase features individual-level data on parliamentary activities, such as voting, speechmaking, and attendance, supplemented by data on Members of the European Parliament and plenary sittings. An accompanying R package offers easy access to the database, and additional identifiers allow for linkage to other core political science data sets. As a result, EuroParlBase facilitates large-N, computational analyses of legislative behaviour, decision-making, and political representation in the European Parliament.