This presentation introduces the U.S. Mass Timber Floor Vibration Design Guide, a new resource available to practicing engineers looking for guidance on floor vibration in mass timber projects. In most floor applications, the design of mass timber panels and framing is controlled by limiting floor vibrations perceived by occupants or sensitive equipment rather than by strength or deflection requirements. While vibration design is not a code requirement in the U.S., it is widely recognized as having a significant impact on the economy and selection of mass timber floors. Prior to publication of the guide, practicing engineers have had few resources with which to determine the vibration performance of a specific mass timber floor. This presentation will introduce the topic of mass timber floor vibration and walk through the contents of the U.S. Mass Timber Floor Vibration Design Guide, including basic vibration theory, calculation methodologies, modeling and post-processing, and three example floor designs.