Multi-storey cross-laminated timber (CLT) buildings are being increasingly built in earthquake prone regions. However, given the relative novelty of this building system, there is a lack of detailed studies on the influence of CLT panel fragmentation levels on their seismic performance. This paper presents an examination of the influence of panel fragmentation on the seismic demands of multi-storey timber buildings by means of advanced data science methods. To this end, various feature selection techniques are applied, namely: Correlation analysis, Stepwise regression, and Lasso regression. Numerical results from a large database of nonlinear dynamic analyses involving 69 prototypical CLT buildings under real earthquake ground motions are used. The building database covers mid- to high-rise CLT buildings with different panel geometries and designed to several behaviour factors (q). The influence of panel fragmentation on maximum inter-storey drift ratio, maximum shear forces, and peak floor accelerations is studied. The results indicate that, although the level of panel fragmentation can affect the drift and shear demands of CLT buildings to some extent, it is not an essential parameter for seismic response estimation since it has relatively minor influence on the seismic response of CLT structures which is strongly dominated by the ground-motion.