As COVID-19 spreads worldwide, national (and sub-national) governments and development partners are making use of a rapidly growing body of evidence to develop policies mitigating against this devastating pandemic. Mathematical models and computational simulation models play a unique role to inform resource planning and policy development (among other uses) through scenario analysis and short-term forecasting. Already in the first six months of this outbreak, we have seen many models at the sub-national, national, regional and global level being developed at an impressive speed.