abstract: This talk is based on several results obtained in collaboration with Benoît Bonnet and Zeinab Badreddine. It is devoted to controlled continuity equations on Wasserstein spaces and their optimal control. In particular, I will present an extension of the theory of differential inclusions to the setting of Wasserstein spaces and results on the existence of solutions to state-constrained inclusions. Indeed, it is well known that in classical optimal control, the differential inclusions theory provides efficient tools for investigation of various fundamental questions. Same happens for problems stated on Wasserstein spaces. Then exponential stability of controlled continuity equations, uniqueness of viscosity like solutions to HJB equations and the Pontryagin type necessary optimality conditions will be briefly discussed.