The external hydrostatic buckling behavior of fiber metal laminate (FML) composite cylinders was investigated numerically. The critical buckling pressure predicted by eigenvalue analysis was compared with experimental results. The numerical results showed different modes of buckling and buckling deformation for cylinders of different fiber orientation when subjected to external hydrostatic loading. FML cylinder with 0 /90 fiber orientation exhibited higher buckling strength and lower buckling deformation as compared to FML cylinders of 60 /30 , AE45 , and AE55 fiber orientations. The orientation of fiber has significant influence on the performance of FML composite cylinder as compared to fiberreinforced plastic thickness. The correlation between numerical and experimental results is discussed in terms of buckling strength, circumferential stiffness, and buckling deformations. It was observed that the cylinders were less sensitive to initial imperfections irrespective of fiber-reinforced plastic thickness. In addition, the results of finite element analysis and experimental results indicate good matches.