Soft materials represented by polymers, liquid crystals, and colloids are a class of materials that exhibit a variety of unique functionalities which derive from their non-rigid structures. In particular, soft metal complexes incorporating flexible long alkyl chains in their structures have been shown to display synergy between the structural dynamics of the long alkyl chain moieties and the electron dynamics occurring at the metal centre. This review presents a discussion of such soft metal complexes with a focus on spin crossover (SCO) behaviours that are associated with a structural phase transition, including a liquid crystal (LC) transition, arising from the flexible natures of the respective complexes. We also discuss how to fabricate soft materials based on SCO complexes.