This study investigated the capability of widely-used finite element modelling (FEM) methods, to predict the flexural capacity behaviour of concrete-filled spiral-welded mild-steel and stainless-steel tubes (CF-SWMSTs and CF-SWSSTs). For this purpose, twelve CF-SWMST and CF-SWSST flexural tests each were modelled using the ABAQUS software. The main parameters that had been varied in the respective tests were the outside diameter to thickness (D/t) ratio and infill concrete strength. The nominal D/t of the modelled specimens were in the range 51–114.5, while the infill concretes were of nominal grades 20 and 50 MPa. The moment capacities predicted by the FEM were observed to be, on average, conservative for the modelled CF-SWMSTs. The predicted flexural capacities were more closely in agreement with the corresponding experimental capacities for the CF-SWSSTs. The respective average actual to predicted moment capacity ratios were 1.07 and 1.00, respectively. The experimental and predicted deformation modes were also in qualitative agreement, with local buckling also being predicted by the finite element models. Though the experimentally obtained local buckling patterns were not exactly replicated, there was, nonetheless, good qualitative agreement. This study provided evidence of the capacity of commonly used FEM approaches, relating to CFSTs, to act as a predictive tool for CF-SWMSTs and CF-SWSSTs in flexure. Given the distinct difference in capacity prediction conservativeness, the study also indicated that separate material model formulations may be warranted for CF-SWSSTs compared to CF-SWMSTs. The predicted results were also found to be negligibly sensitive to explicitly modelling the spiral weld seam geometry, even though it was the default case adopted for the FEM in this study.