Plate or nail fixations have been applied to the repair of clavicle fractures. However, it is quite difficult to fairly evaluate the different clavicle fixation techniques owing to variations in the bone anatomy, bone quality, and fracture pattern. The purpose of this study was to investigate the biomechanical performances of different fixation techniques applied to a clavicle fracture using the finite element method. A simplified single-clavicle model and a complete human upper-body skeleton model were developed in this study. Three types of plate fixations, namely, superior clavicle plate, anterior clavicle plate, and clavicle anatomic spiral fixations, and one nail fixation, a titanium elastic nail fixation, were investigated and compared. The plate fixation techniques have a better fixation stability compared to the nail fixation technique. However, the nail fixation technique shows lower bone stress and can reduce the risk of a peri-implant fracture compared to the plate fixation techniques. Increasing the number of locking screws for the clavicle plate system can reduce the implant stress. Insertion of the bone plate into the anterior site of the clavicle or a multi-plane fixation is recommended to achieve the required biomechanical performance. A plate fixation revealed a relatively better fixation stability, and a nail fixation showed a lower risk of a peri-implant fracture.