This paper focuses on the leader-follower consensus problem in linear multi-agent systems (MASs) under bounded exogenous disturbances. A distributed state-feedback control protocol is proposed using a Proportional–Integral Fading Observer (PIFO), which simultaneously estimates and compensates for unknown disturbances affecting each agent. By designing a distributed consensus control strategy that uses local relative state information and disturbance estimates, we derive sufficient conditions under which leader-follower consensus is asymptotically achieved and rigorous Lyapunov-based stability analysis is presented to establish the convergence of both consensus and estimation errors. The simulation results validate the theoretical analysis and demonstrate the effectiveness of the proposed approach in accurately rejecting disturbances and achieving consensus.