Tropical cyclone (TC) risk assessments are critical for disaster preparedness and response. Alongside hazard and exposure, accurate TC risk assessment requires understanding the vulnerability of populations and assets. In this chapter, we examine multiple methods that have been used to assess and quantify TC vulnerability with a focus on open-source methods. We separately discuss structural, economic, and social (or demographic) vulnerability approaches. Structural vulnerability assesses the susceptibility of buildings to be affected by their exposure to hazards; in this section, we provide a detailed overview of how FEMA’s Hazus model quantifies damages by utilizing engineering principles. Economic vulnerability employs regression analysis to relate wind speeds to damages; this discussion explores typical functional forms used to represent vulnerability in such analysis and efforts to constrain parameters in these functions. Finally, social approaches use demographic data to characterize the varying susceptibility of populations to TC risk; we provide some representative examples of this methodology. We conclude with a comparative discussion of these three classes of methods, suggest directions for future work, and ask whether the different approaches can be combined to yield a more holistic view of both the human and structural aspects of TC vulnerability.