The International Workshop on Algorithms and Theories for the Analysis of Event Data (ATAED 2025) took place on June 24, 2025, in Paris. The workshop was co-located with the 46th International Conference on Application and Theory of Petri Nets and Concurrency (PETRI NETS 2025). The aim of ATAED is to bring together researchers working on theoretical foundations and practical approaches related to the analysis of event data. This includes deriving higher-level process models, such as various classes of Petri nets, BPMN diagrams, or UML activity diagrams, from lower-level behavioral descriptions like event logs, sets of partial orders, or transition systems. The workshop is supported by the IEEE Task Force on Process Mining and the Fachgruppe ”Petrinetze und verwandte Systemmodelle” of the German Informatics Society. It represents a joint efort by researchers from both fields. The topics of interest for the workshop include, but are not limited to: theory and applications of process mining and region theory, event-based predictive analytics, process mining in big data environments, automated business process model discovery, conformance checking, alignments and replay algorithms, process monitoring, object-centric and partially ordered event logs, decision mining techniques, real-time process mining, trace clustering methods, architectures for distributed process mining, and empirical investigations and case studies based on event data. Further information about the workshop is available at: www.fernuni-hagen.de/ataed This year, we received six submissions for inclusion in these proceedings. Each paper was reviewed by at least three referees. Based on the review process, the program committee selected four contributions for publication. We would like to thank all members of the program committee and the local organization team in Paris for their support.