Demographic models can have two meanings, one broad and one narrow. In its broad meaning, demographic models refer to all mathematical, statistical, forecast, and microsimulation models that are applied to studies of demographic phenomena. In its narrow meaning, demographic models refer to empirical regularities in age patterns of demographic events. This article is concerned with demographic models in the narrow definition. Demographic models are widely used (a) to improve data quality and (b) to compare demographic outcomes and processes across populations or subpopulations. Both parametric and semiparametric specifications have been proposed for modeling age patterns of demographic events, giving rise to parametric models and semiparametric models. Successful applications of both types of models are found in research on mortality, nuptiality, and fertility. As an integral part of formal demography, demographic models have been linked closely to mathematical demography. In recent decades, however, statistical demography has played an increasingly important role in demographic models.