Apparatus, systems, methods, and articles of manufacture for tracking a trajectory by rotorcraft unmanned aerial vehicles (UAVs) are described herein. An example trajectory tracking controller includes an altitude controller to calculate an output value of a thrust control variable based on a trajectory of a rotorcraft independent of one or more system parameters of the rotorcraft. The example trajectory tracking controller also includes an attitude controller to calculate output values of roll, pitch, and yaw control variables based on the trajectory independent of the one or more of the system parameters. The example trajectory tracking controller further includes a motor speed selector to select speeds for propeller motors of the rotorcraft based on the output values of the thrust, roll, pitch, and yaw control variables and activate the propeller motors based on the selected motor speeds.