We study AdS duals of four-dimensional (4D) N = 1 superconformal field theories (SCFTs) on Z k S-folds with T-branes that flow to 4D N = 3 theories. In a previous study, it was discussed how considering T-brane structure breaks the N = 2 supersymmetry in 4D SCFTs on Z k S-folds down to N = 1. In this study, we analyze this effect from the AdS perspective and find that the T-brane effect, seen from the AdS perspective, deforms the horizon geometry from S 5 /Z k into S 5 /Γ, where Γ is a finite subgroup in SU (3). We also discuss the constructions of 4D N = 1 SCFTs on S-folds with T-branes starting from global K3 hypersurfaces whose fibers involve complex multiplications. We choose an approach to directly analyze the global K3 geometry without relying on the standard Weierstrass technique.