Provided are: an epoxy resin composition which enables the production of a carbon-fiber-reinforced composite material having excellent tensile strength and compressive strength and suitable as a material for structures; a prepreg; and a carbon-fiber-reinforced composite material. An epoxy resin composition characterized by comprising at least [A] an epoxy resin having a structure represented by formula (1), [B] an epoxy resin having at least one amine-type glycidyl group or at least one ether-type glycidyl group and having a liquid form at 40° C. and [C] a curing agent; and a prepreg and a carbon-fiber-reinforced composite material, each produced using the epoxy resin composition. (In the formula, R1 to R4 independently represent at least one atom or group selected from the group consisting of a hydrogen atom, an aliphatic hydrocarbon group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 4 or less carbon atoms, and a halogen atom.)