Stacking fault (sf) and twin defects in Pd, Au–Pd, and Au–Pd–Pt clusters are theoretically studied, which has affected the mechanical properties of face centered cubic (fcc) metal and alloy clusters. The stable structures are located with Gupta potential by the density functional theory (DFT)-fitted and averaged parameters. In Pd_30–200 clusters, besides morphologies, such as Mackay icosahedra (Ih) and Marks decahedra (Dh), fcc, sf-fcc, and twin-fcc motifs are identified. Furthermore, the growth pattern of twin-fcc is based on the 50- and 79-atom motifs with high D_3h symmetry, and the construction method for all possible D_3h twin-fcc is proposed starting from centered and uncentered truncated octahedra. Moreover, a strong competition among fcc, sf-fcc, twin-fcc, Ih, and Dh is found in Au_mPd_n (m + n = 50 and 61) and 55-atom Au–Pd–Pt clusters. The segregation phenomena of the Au, Pd, and Pt atoms in the Au–Pd–Pt clusters are studied and further compared with Au–Pd, Au–Pt, and Pd–Pt clusters.