A flame-retardant thermoplastic polyurethane resin composition is provided, containing: a thermoplastic polyurethane resin; at least one melamine salt selected from the group consisting of melamine orthophosphate, melamine pyrophosphate, and melamine polyphosphate; at least one piperazine salt selected from the group consisting of piperazine orthophosphate, piperazine pyrophosphate, and piperazine polyphosphate; and wet process silica having an oil absorption of 200 ml/100 g or more. The composition preferably contains zinc oxide.