Floating bridges have attracted great interests in coastal countries for sea-crossing transportation infrastructures, such as Norway, Japan, Singapore, etc. Wave and traffic loads are two critical actions to be taken into consideration in the dynamic analysis of floating bridges, which involves both fluid–structure and vehicle-bridge interactions. This paper presents a fully coupled computational fluid dynamics (CFD)—finite element method (FEM) approach to predict dynamic responses of pontoon-type floating bridges when subjected to combined wave and traffic loads. The sophisticated numerical model is developed using ABAQUS and Star-CCM + co-simulation software platform, where a two-way data communication scheme is applied between CFD and FEM solvers. CFD simulation exports the fluid pressure for the determination of structural responses in the FEM solver, while pontoon motions are fed back to deform the mesh in the CFD solver. Moving vehicles are idealized as mass-spring-damper mechanical systems and the floating bridge is modeled with beam and plate elements. A simple traffic model composing of different numbers of trucks is adopted to assess the vehicle-induced dynamic response of the floating bridge. Research outcome indicates that the traffic load causes downward effects on the dynamic response of pontoon-type floating bridges. The traffic-induced dynamic impact effect varies with different spans of the floating bridge. Dynamic responses caused by the simple multi-truck load are relatively small as compared with wave action effects, and the random traffic load model is suggested to be considered in the engineering practice.