Defects and their dynamics play a fundamental role in controlling both equilibrium and timedependent properties of materials. Extended crystallographic defects, such as stacking faults and dislocations, underpin the mechanical plastic behavior of metals. Atomic impurities that enter the lattice of semiconducting materials can be used as dopants to fine-tune their electronic properties. While the concept of defects is typically associated to crystals, or in general to highly ordered structures, they play a key role also in softer materials, although their identification in such dynamic and disordered systems can be way more elusive. Supramolecular polymers are generated by directional self-assembly of monomers that interact via non-covalent interactions such as hydrogen bonding, ππ stacking, etc. While in these systems the interactions between the monomers are generally weak compared to covalent bonds, their reversible character imparts interesting dynamic properties to these materials that are similar to those of natural compounds and impossible to achieve with covalent polymers. In these systems, the self-assembled monomers obey a well-defined supramolecular equilibrium with the monomers present in solution. This makes these structures innately dynamic, while the constitutive monomers are continuously exchanged depending on their interactions with each other and with the external solvent. Many approaches have been designed to characterize the structure and dynamics of supramolecular polymers. However, the limited resolution that can be achieved in the experiments makes it a challenge to resolve unambiguously the molecular factors that control the behaviour of these complex systems.