PROBLEM TO BE SOLVED: To provide a resin composition that is in a white or pale color and has both of high weather resistance and flame retardancy.SOLUTION: A weather-resistant flame-retardant resin composition is provided, which comprises: to 100 parts by mass of a polyolefin resin; 10 to 50 parts by mass in total content of a mixture of a first (poly)phosphate compound expressed by a predetermined general formula and a second (poly)phosphate compound expressed by a predetermined general formula; 0.1 to 5 parts by mass in total content of a mixture of a photostabilizer and an organic UV absorbent; and 0.1 to 20 parts by mass in total content of an inorganic UV screening agent. In the composition, a mass ratio of the content of the photostabilizer to the content of the organic UV absorbent ranges from 2:8 to 8:2. An electric wire and an optical fiber cable having a sheath formed from the weather-resistant flame-retardant resin composition are also disclosed.
