Resilience is recognized as a critical property of complex social-ecological-technological systems (SETS). Yet, its modeling remains fragmented, often lacking semantic rigor, reusability, and cross-domain applicability. This paper introduces LaDeRR (Language for Describing Risk and Resilience), a novel domain-specific modeling language (DSML) grounded in ResiliOnt—a well-founded core ontology for resilience. LaDeRR enables the formal specification and analysis of resilience scenarios through constructs representing capabilities, vulnerabilities, threats, and emergent resilience configurations. It supports a complete workflow, including textual syntax, RDF-based representation, semantic validation with SHACL, rule-based inference, and automated visualization. LaDeRR explicitly supports both proactive design-time analysis and retrospective modeling, allowing users to formally specify and analyze both ongoing and past resilience scenarios. This dual capability supports improved decision-making and long-term resilience planning. A representative case study in supply chain disruption demonstrates LaDeRR’s expressiveness in identifying system vulnerabilities, modeling resilience strategies, and evaluating dynamic scenario outcomes. By integrating ontological precision with robust computational support leveraging logical reasoning, LaDeRR helps bridge the gap between theoretical foundations and applied resilience engineering.