The concept of essential work of fracture is implemented for characterizing the raster-orientation-dependent fracture behavior of 3D printed PEEK polymer for the first time. The fracture tests are carried out on various 3D printed double-edge-notched-tension specimens of constant thickness but different raster orientations. It is observed that the fracture initiation energy has a strong dependence on the raster orientation and attains the highest value for 0° raster orientation (printing direction perpendicular to the crack plane) and the lowest value for 90° raster orientation (printing direction parallel to crack plane). The fracture tests have indicated that the ductility levels of the samples and size of plastic zone developed within the ligament region are also controlled by the raster orientation. In addition to fracture tests, the fractured surfaces of the test samples are also examined to identify the dominant failure mechanisms. The detailed analysis carried out in this study provide guidelines in making fracture resistant 3D printed PEEK components.