Singlet fission is a form of multiple exciton generation in which two triplets are produced from the decay of a photoexcited singlet exciton. This process has only been observed in a few classes of organic materials to date, most notably the oligoacenes. Of these materials, efficient singlet fission occurs only in highly ordered media, with the singlet fission rate and total yield being sensitive to both local and long-range order. A particular challenge is the ability to synthesize families of materials capable of an intramolecular fission process, where two triplets are produced on the same molecule, independently of intermolecular coupling or other interactions. This talk will highlight strategies that couple modular chemical design with mechanistic studies of intramolecular singlet fission in molecules and polymers.