<p>This study investigates the effect of Ce substitution on the microstructure and magnetic domain characteristics of (Nd, Ce)-Fe-B sintered magnets. The impacts of varying Ce content on the crystal structure, composition distribution, domain structure, and grain orientation were systematically analyzed. The results reveal that increasing Ce leads to a more complex domain structure, with reversed wedge-shaped domains, along with additional branching features at domain walls and a reduction in domain size. These changes result from a decrease in anisotropy with Ce incorporation. Additionally, Ce substitution increases the formation of REFe₂ phases at the grain boundaries. This disrupts the coupling between the main-phase and grain boundary regions, yielding a more inhomogeneous microstructure and poorer grain orientation. Electron-backscatter-diffraction-analysis demonstrates that the variation in domain deflection along the <Emphasis Type="BoldItalic">c</Emphasis>-axis is a reliable indicator of orientation in (Nd, Ce)-Fe-B sintered magnets. These findings provide valuable insights for optimizing the microstructural design of rare-earth permanent magnets.</p> Graphical abstract <p></p>