A flame-retardant resin composition comprising a biodegradable resin and flame-retardant particles having a volume average particle diameter in the range of 1 nm to 500 nm dispersed in the biodegradable resin, wherein the flame-retardant particles contain a metal hydrate and have a coating layer containing an organic compound or a polysilicone, and a flame-retardant resin-molded article comprising a biodegradable resin and flame-retardant particles having a volume average particle diameter of 1 nm to 500 nm dispersed in the biodegradable resin, wherein the flame-retardant particles comprise a metal hydrate, and the flame-retardant resin-molded article has a flame retardancy of HB or higher according to the UL-94 test.