In the present work we report a theoretical study of magnetically-induced Pekar–Rashba spin splitting in antiferromagnetic monolayers of both layered and nonlayered crystals. We outline a detailed two-step procedure for determining magnetic layer group of a given monolayer, and classify all the magnetic layer groups into seven spin splitting prototypes. The latter classification allows one to determine on the basis of symmetry arguments whether spin splitting is prohibited or allowed in a given monolayer. In the latter case, the magnitude of spin splitting must be determined from Density Functional Theory calculations. The above procedure is implemented using both layered (MnPS₃) and nonlayered (MnO₂) crystals as illustrative examples.