Vibration attenuation in rotating machines is typically addressed by improving the design of machine foundations and bearings. In this context, the use of metamaterials for vibration control presents an alternative to classical methods. Metamaterials can be designed using periodic structures, locally resonant effects, or a combination of both. While locally resonant metamaterials have been proposed before, particularly because their mechanical design can be challenging. This study presents the design of a locally resonant device attached to a shaft that rotates with it, along with experimental evidence of vibration attenuation using metamaterial-based systems in a rotor setup. The target structure consists of a shaft supported by two bearings, with an unbalanced inertial disk attached at its midpoint. Resonators are evenly distributed on either side of the shaft and are produced using additive manufacturing with PLA. To measure the rotor’s vibration, proximity sensors are placed near the inertial disk. The design of the resonators aims to achieve attenuation at the lowest vibration mode, which is excited at multiples of the shaft frequency across various rotating frequencies. The performance of the attenuation is assessed using the frequency response function, estimated from a hammer impact test. The results indicate that the resonators can reduce the vibration response when compared to the bare rotor. This experimental evidence opens new possibilities for vibration control in rotordynamics applications.