Citric acid, naturally occurred in citrus fruits, is also known as an intermediate for cellular energy production in the Krebs cycle. Leveraging the multifunctional nature of citrate in chemistry and inspired by its important biological roles in human tissues, a class of highly versatile and functional citrate-based biomaterials has been developed. In this presentation, a methodology for the design of biomimetic citrate biomaterials and their applications in regenerative engineering, drug delivery, bioimaging and biosensing will be discussed.