As data quality becomes mission-critical in digital ecosystems, this workshop focuses on how semantic technologies can be used to validate data effectively and declaratively. Participants will explore how RDF data can be validated using technologies like SHACL (Shapes Constraint Language) and SPIN, enabling consistency, compliance, and interoperability in knowledge graphs and Linked Data applications. Through hands-on examples, this workshop will teach participants how to define constraints on data models, detect errors or inconsistencies, and integrate validation into data pipelines — all using semantic web standards.