This study investigates various surface finishes on the low cycle fatigue properties of laser powder bed fusion GRCop-42. The surfaces evaluated include as-built, machined, and chemical mechanical polishing with two surface finishes (1 .0% and 2 .0%). Additionally, the LCF life of polished GRCop-42 was assessed across a range of temperatures, including cryogenic (−195 ◦ C ), ambient, and elevated temperatures (200 ◦ C , 400 ◦ C , 600 ◦ C , and 800 ◦ C ), at three fatigue strain amplitudes: 0 .7%, 1 .0%, and 2 .0%. It was found that surface finish does not significantly affect the LCF life of the specimens since specimens with the as-printed surface exhibited a similar fatigue life to that of machined and polished specimens. In contrast, temperature significantly influences the fatigue life, with the average fatigue life decreasing as temperature increases. Furthermore, stress was examined as a function of fatigue life at different strain levels. The surface finish shows little effect on the cyclic hardening/softening, with all exhibiting an initial cyclic hardening followed by progressive cyclic softening. We found that the testing temperature from cryogenic to elevated temperature induces a deformation transition, affecting the material’s cyclic hardening and softening behavior. Cryogenic temperatures led to cyclic hardening followed by cyclic stabilization, while ambient temperature and 200 ◦ C displayed initial cyclic hardening followed by progressive cyclic softening. Specimens tested at 400 ◦ C and above displayed cyclic softening throughout the test. Finally, fractographic analysis demonstrated that surface finish impacted the plastic deformation, where specimens with the as-printed and polished surfaces had a brittle fracture while machined specimens showed a more ductile behavior. Moreover, specimens tested at cryogenic and ambient temperatures exhibited brittle fractures, while specimens tested at elevated temperatures displayed plastic deformation and secondary cracks on the gage section. Additionally, increasing the test temperature led to shorter and broader secondary cracks.