This paper presents the design and co-simulation of a semi-active suspension system for a seven-seat passenger vehicle to enhance ride comfort and handling stability. A full-vehicle model is developed using specialized software and integrated into MATLAB/Simulink. The Magnetorheological (MR) damper is modelled using the Bouc–Wen approach to reflect its nonlinear hysteresis behaviour under varying magnetic fields. A Fuzzy Logic Controller (FLC) is designed to regulate damping force based on real-time suspension deflection and jounce rate. Simulations are conducted under half-sine and random road excitations at vehicle speeds of 35 km/h and 50 km/h. The proposed semi-active suspension demonstrates significant improvements compared to the passive system, achieving up to 14.5% reduction in body displacement and up to 36.5% in vertical acceleration (RMS). These results confirm the effectiveness of MR dampers combined with intelligent control in improving ride quality, offering a promising solution for advanced suspension systems in modern vehicles.