A wheel-side reducer system includes a housing, a speed reduction assembly, and a steering knuckle. The housing includes a front housing and a rear housing. The front housing and the rear housing are arranged opposite to each other and define an accommodating space together. The speed reduction assembly is arranged in the accommodating space. The steering knuckle is integrally molded on the front housing. The integrally molding of the steering knuckle on the front housing not only simplifies the production process of the housing, but also makes a connection between the steering knuckle and the front housing more reliable. Meanwhile, the integration level of the wheel-side reducer system can also be improved, to reduce the size of the wheel-side reducer system. A vehicle with the wheel-side reducer system is further disclosed.