Structural components made of fibre-reinforced polymers offer great potential for high-performance applications in lightweight construction. However, composites can exhibit a complex local material structure with spatially varying fibre orientation and fibre volume content (FVC), particularly in the joining zones of fibre-reinforced thermoplastics (FRTP). Because the formation of this local structure during manufacturing in some cases cannot yet be accurately predicted by numerical process simulation, experimental characterisation was required as an alternative basis for virtual structural analysis. In this study, a multi-layered unidirectional glass fibre (GF)/polypropylene (PP) composite was investigated as the model material system. X-ray computed tomography (CT) was used to characterise fibre orientation, FVC, and porosity within a defined volume element extracted from a shear tension test specimen. The CT-derived microstructural data were subsequently evaluated across a range of mesh resolutions and prepared for systematic transfer to finite element (FE) models. The fibre orientation proved robust with respect to the mesh resolution, with a median deviation of about 1^∘. The FVC and detectable internal porosity were additionally checked for plausibility against a calcination measurement and a density-based estimate.