Modeling can play a critical role in assessing and mitigating risks posed by natural hazards. These modeling efforts generally aim to characterize the occurrence, intensity, and potential consequences of natural hazards. Uncertainties surrounding the modeling process can have important implications for the development, application, evaluation, and interpretation of models. In this chapter, we focus on the analysis of model‐based uncertainties faced in natural hazard modeling and decision support. Uncertainty analysis can help modelers and analysts select appropriate modeling techniques. Further, uncertainty analysis can ensure decision processes are informed and transparent, and can help decision makers define their confidence in model results and evaluate the utility of investing in reducing uncertainty, where feasible. We introduce a framework for identifying and classifying uncertainties, and then provide practical guidance for implementing that framework. We review terminology and offer examples of application to natural hazard modeling, culminating in an abbreviated illustration of uncertainty analysis in the context of wildfire and debris flow modeling. The objective of this brief review is to help readers understand the basics of applied uncertainty theory and its relation to natural hazard modeling and risk assessment.