Abstract Topographically complex interfaces offer a promising route to engineer magnetic textures in oxide thin films, with potential implications for next‐generation spintronic and neuromorphic devices. Here, Fe 3 O 4 thin films are grown on self‐assembled SiO 2 nanospheres to investigate how local curvature, together with polycrystalline morphology, influence magnetic behavior compared to flat films. STEM and GISANS confirm connected growth with preserved lateral ordering, while XMCD‐PEEM reveals in‐plane magnetic domains that extend across both nanosphere‐patterned and flat regions. Despite the low net magnetization of the Fe 3 O 4 caps, their domain orientations align with neighboring flat areas, indicating correlated domain behavior across structurally different regions. These findings demonstrate how nanoscale topography and morphology can be leveraged as design parameters to modulate magnetism in complex oxides.