Adipose tissue engineering has recently gained significant attention from materials scientists as a result of the exponential growth of soft tissue filler procedures being performed within the clinic. While several injectable materials are currently being marketed for filling subcutaneous voids, they often face limited longevity due to rapid resorption. Their inability to encourage natural adipose formation or ingrowth necessitates repeated injections for a prolonged effect and thus classifies them as temporary fillers. As a result, a significant need for injectable materials that not only act as fillers but also promote in vivo adipogenesis is beginning to be realized. This paper will discuss the advantages and disadvantages of commercially available soft tissue fillers. It will then summarize the current state of research using injectable synthetic materials, biopolymers and extracellular matrix-derived materials for adipose tissue engineering. Furthermore, the successful attributes observed across each of these materials will be outlined along with a discussion of the current difficulties and future directions for adipose tissue engineering.