Orientation-dependent vortex fluidic processing of aqueous alkali lignin at a fixed tilt angle of 45° enables its conversion into nanosheets with controllable morphology. Under optimised rotational speeds and processing times, clockwise (CW) and counterclockwise (CCW) operation, combined with orienting the VFD toward the south, east, north and west directions, generate distinct shear profiles within the dynamic thin film, driving anisotropic assembly and exfoliation of lignin. This results in morphology transitions from irregular particulates to extended, sheet-like nanostructures, with specific directional conditions favouring higher aspect ratio nanosheets and reduced aggregation. The use of water as the sole solvent establishes a green processing platform, leveraging hydrodynamic shear rather than chemical modifiers to induce structural reorganisation. Collectively, these findings demonstrate that coupling flow topology (CW/CCW, orientation) with thin-film shear in a VFD provides a powerful handle for directing lignin nanostructure formation, advancing sustainable advanced manufacturing of bio-derived nanosheet materials.