There are provided a thermoplastic elastomer composition from which a molded article excellent in softness, flame retardancy, tensile properties, and appearance can be obtained and which is excellent in flowability, and a molded article thereof. The thermoplastic elastomer composition includes a thermoplastic elastomer obtained by reacting an ethylene copolymer comprising monomer units derived from ethylene and monomer units derived from at least one selected from the group consisting of propylene and α-olefins having 4 to 10 carbon atoms (component (A)), a propylene polymer (component (B)), and a crosslinking agent, a phosphoric acid salt compound (component (C)), a metal oxide including a metal having an atomic weight of 22 to 64 or a metal hydroxide including a metal having an atomic weight of 22 to 64 (component (D)), and a polyhydric compound (component (E)).