<p>Anisotropic colloidal systems, such as graphene oxide, MXene, and cellulose nanocrystal suspensions, exhibit complex viscoelastic behavior due to their unique microstructural arrangements, including liquid crystallinity, domain alignment, and network formation. This review outlines recent advances in rheological methodologies used to characterize and interpret their nonlinear viscoelastic responses. Conventional oscillatory shear testing provides fundamental parameters—storage (G′) and loss (G″) moduli—used to identify the linear viscoelastic region, yield point, and flow point, and to relate these to structural deformation mechanisms. More advanced techniques, including Fourier-transform rheology (FT-rheology), Lissajous–Bowditch (L–B) curve analysis, and Sequence of Physical Processes (SPP) analysis, enable quantitative evaluation of intra-cycle nonlinearities and transient structural evolution. Steady shear flow measurements further link the viscosity to liquid crystal phase and shear-induced alignment. By integrating modulus-based, intracycle local parameters, or transient parameters with structural characterization tools such as rheo-SAXS and rheo-PLI, a more complete understanding of the relationship between microstructure and rheological response is achieved. As anisotropic colloidal systems evolve and their applications diversify, the role of rheology in guiding material and process design for tailored performance is expected to become increasingly significant, particularly for high-performance coatings, printable formulations, and stimuli-responsive functional materials.</p> Graphical abstract <p></p>