The two-volume set LNCS 14744 + 14745 constitutes the proceedings of the 28th International Conference on Financial Cryptography and Data Security, FC 2024, which took place in Willemstad, Curaçao, during March 4-8, 2024. The number of 36 full and 6 short papers included in the proceedings were carefully reviewed and selected from 199 submissions. They were organized in topical sections as follows:  Part I: Consensus; AMMs; fees and rewards; hardware attacks;  Part II: Feeling Optimistic; randomness and time; signatures; applied cryptography; PETS; designing for the real world.