Ductile damage in a metal takes place due to void nucleation, growth, and coalescence. The mechanism depends heavily on the material micro-structure in terms of second-phase particles and grain characteristics. While details of void nucleation are often modelled based on explicit details of the micro-structure, subsequent void growth and coalescence may be modelled using homogenized continuum mechanics frameworks. The current study analyses the damage development in an Al-1050 aluminium alloy using the finite element method, supported by an in-situ X-ray Computed Tomography (XCT) experiment, carried out under quasi-static monotonic loading well into the necking stage. The Gurson–Tvergaard–Needleman (GTN) model describes the development of porosity as characterized by the Void Volume Fraction (VVF). The GTN model is employed to predict the growth of VVFs. Although a good agreement between the experiment and the modelling is obtained, in terms of engineering stress as a function of engineering strain, the VVFs obtained from the XCT experiment exhibit a random distribution highly dependent on the choice of representative volume element, which the GTN model does not capture. The statistical GTN model is therefore used to study the effect of the random initial void volume fraction on the ductile damage.