In this paper discusses various algorithms on optimal tuning Fractional-Order Proportional Integral Derivative (FOPID) controller to govern the rotor speed of sensorless Brushless Direct Current (BLDC) motor. Bat Algorithm (BA) is used as the optimization algorithm for developing a novel approach to generate five degrees of freedom parameters namely kp, ki, l and m of FOPID controller. A robust performance is achieved by using the FOPID closed loop speed controller using BA for optimal tuning along with a control on the desired speed. The study measured the time domain specifications of a dynamic system for unit step input to FOPID controller for speed response such as peak time ( tr), Percentage of overshoot (PO), settling time (ts), rise time (tr) have been evaluated and the steady-state error (ess) of sensorless speed control of BLDC motor. The characteristics are compared with the results from Artificial Bee Colony (ABC) and Modified Genetic Algorithm (MGA) for transient and steady state time domain. The results confirm that the proposed controller optimization using BA technique is more efficient in improving the transient characteristic performance and reducing steady state error for the FOPID.