This study presents the design and implementation of a spatial H-infinity controller for the active vibration control of a cantilevered smart beam. The smart beam consists of a passive aluminum beam (507x51x2mm) and eight symmetrically surface bonded SensorTech BM500 type PZT (Lead-Zirconate-Titanate) patches (25x20x0.5mm). PZT patches are used as actuators and a laser displacement sensor is used as sensor. The smart beam was analytically modelled by using the assumed-modes method. The model only included the first two flexural vibrational modes and the model correction technique was applied to compensate the possible error due to the higher order modes. The system model was also experimentally identified and both theoretical and experimental models were used together in order to determine the modal damping ratios of the smart beam. A spatial controller was designed for the suppression of the vibrations of the smart beam due to its first two flexural modes. The designed controller was then implemented to experimentally suppress the vibrations. This study also compared the effectiveness of a pointwise controller with the newly developed spatial one.