A flame-retardant resin composition containing a base resin composed of polyethylene and an acid-modified polyolefin, aluminum hydroxide, a silicone compound, and a fatty acid-containing compound. The flame-retardant resin composition may contain polyethylene with a density of 912.4 kg/m3 or less. The base resin may contain an amount of polyethylene of the range 80 to 99% by mass, the amount of the acid-modified polyolefin in the base resin is of the range 1 to 20% by mass. To 100 parts by mass of the base resin, the aluminum hydroxide may be added in an amount of the range 5 to 190 parts by mass, the silicone compound may be added in an amount of the range 1.5 to 10 parts by mass, and the fatty acid-containing compound may be added in an amount of the range 5 to 20 parts by mass.