An optimal direct robust adaptive fuzzy controller (ODAFC) for a quadrotor system using bat algorithm (BA) is presented in this paper. The concept of this approach is to decouple the entire system into four single-input single-output (SISO) subsystems. Then, a Mamdani-type fuzzy adaptive controller and a compensated control term are employed using tracking error universe in direct control for each subsystem. After, the BA is used to determine the optimal values of the adaptation parameters. The proposed control scheme completely overcomes the singularity problem that occurs in the indirect adaptive control. The stability of the quadrotor control system, which is based on the Lyapunov theory, is guaranteed. Simulation results demonstrate the capability and the efficiency of the proposed technique even with uncertainties and external disturbances.