This study calculates the stress concentration factor of flat and curved PLA plate structures and studies the stress features surrounding holes of the plate structure. It is essential to understand the stress behaviour of 3D-printed PLA plates around the hole. Flat and curved plates with holes of 40 mm, 20 mm, and 10 mm in diameter were investigated. With a 2.5 N/mm2 applied load to the plate, such models were put through finite element analysis and simulations using ANSYS to investigate the maximum stress in the longitudinal direction. The result was then compared to the theoretical result. The results show that for the curve radius of 100 mm, decreasing the hole diameter of 0.04, 0.02 and 0.01 m increases the stress concentration factor of 2.18, 2.41 and 2.68 respectively. The stress versus diameter graph for elements with dimensions of 5 mm, 4 mm, and 2 mm compares the maximum stress between analysis methods and finite element analysis. The results show that for the curve radius of 100 mm hole diameter of 40, 20 and 10 mm with element size of 2 mm, will produce the decreasing maximum stress of 10.7063, 8.0046 and 7.5529 MPa. The Stress Concentration Factor (Kt) vs. Plate Diameter graph indicates that the stress concentration factor increases with decreasing diameter. The maximum stress is demonstrated to be decreasing as the hole gets smaller.