Due to the lightweight nature of timber, vibration serviceability is a crucial issue in the design of timber floors. The purpose of this study is to investigate how beam–panel connections affect the vibration serviceability of cross-laminated timber (CLT) floors subjected to multi-person loading. Cyclic tests were carried out to determine the mechanical behaviour of steel beam–CLT panel connections with various screws sizes (diameters and lengths). A numerical model of a CLT floor was developed to determine the response to human-induced vibrations with different screw configurations (sizes and spacing). The results showed that the dynamic characteristics of the floor were slightly impacted by the screw size. However, as the spacing between screws reduced, the fundamental natural frequency increased by 4.3% and the vibration dose value (VDV) of the floor decreased by 38.3%. A theoretical model was introduced to predict the fundamental natural frequency of a CLT floor system. In addition, a design method for predicting the vibration serviceability, in terms of VDV, of low-frequency CLT floors was proposed.