The effects of corrosion on clinched joints are not completely understood yet. Recent research indicates that galvanic corrosion can actually enhance the fatigue life of clinched joints. It is then of significant interest to investigate the effects of another corrosion phenomenon, pitting corrosion, on the fatigue behavior of clinched joints. Pitting corrosion occurs in passive metals and can lead to stress concentrations. In the present study, the effects of pitting corrosion are investigated by using Lemaitre’s two-scale fatigue model with a 2D geometry of clinched joints. A slip condition is applied as a boundary condition to simplify the clinched joint model and reduce the computational cost of solving the contact mechanics problem. Additionally, a method to determine the damage strength and the damage exponent used in the two-scale damage model is introduced. Numerical simulations reveal that pitting corrosion reduces the fatigue life of clinched joints, particularly when it occurs on the internal surface in the neck area.