Here, the authors show that in noncollinear antiferromagnets that have the anomalous Hall effect the net orbital magnetization can dominate the spin magnetization when the spin-orbit coupling is weak. This trend is verified by first-principles calculations on Mn (=Ir, Pt, Rh, Sn, Ge) using modern theory of orbital magnetization. They then discuss how the noncollinear magnetic order parameter is rotated coherently by external magnetic fields, which couple to the dominant orbital magnetization in the framework of relativistic spin density functional theory, and they provide a toy model example based on cubic Mn.