The capability of the recently proposed integral wall model for large eddy simulation (iWMLES) to capture flow separation, transition, and reattachment is investigated by means of flow over a flat plate with a suction and blowing boundary condition. Wall-resolving LES can accurately recover time-averaged DNS results for a laminar separation bubble, but are limited to moderate Reynolds numbers due to the strong requirement of resolving the boundary layer. Typical equilibrium wall-models do not take pressure gradients into account, and many hybrid RANS-LES either rely on the equilibrium assumption or require very fine mesh spacing in the wall-normal direction. iWMLES addresses these deficiencies through the addition of non-equilibrium terms in an integral version of the momentum equation. iWMLES of a laminar separation bubble flow confirm that the wall-model can capture flow separation, transition, and reattachment at Reδ = 105 on a coarse grid. Good qualitative agreement with a wall-resolved LES of a turbulent separation bubble is obtained using iWMLES on a coarser wall-normal grid. Trends in both mean and RMS velocities as well as the coefficient of pressure are well predicted by the iWMLES.