<p>This article investigates the challenging issue of predefined-time event-triggered output feedback consensus for leader–follower second-order multiagent systems (MASs) with actuator faults and input saturation. First, a predefined-time distributed estimator is developed for each follower to estimate the state of the leader. Second, a novel predefined-time extended state observer (ESO) is constructed to simultaneously and accurately estimate the unmeasurable system states and the lumped disturbances in predefined time. Then, a novel predefined-time event-triggered fault-tolerant controller is presented based on the distributed estimator and the predefined-time ESO. Utilizing the approach of Lyapunov analysis, sufficient conditions are derived to ensure the presented scheme is able to realize predefined-time stability and exclude the Zeno phenomenon. Furthermore, the settling time of the presented control scheme is a tunable parameter, which remains regardless of initial values and other design parameters. Finally, representative simulation experiments are conducted to illustrate the effectiveness of the presented control scheme.</p>