The present invention provides a thermoplastic elastomer composition obtained by dynamically crosslinking, under a melting condition, 100 parts by mass of a block copolymer (I), 1 to 1,000 parts by mass of a polar resin (II), 1 to 500 parts by mass of a modified polymer (III), and 0.01 to 50 parts by mass of a crosslinking agent (IV), wherein the block copolymer (I) comprises at least one polymer block (A) comprising as a main component an alkylene unit, and/or at least one copolymer block (B) comprising as main components an alkylene unit (b-1) and a vinyl aromatic monomer unit (b-2), and comprises at least one unsaturated block (C) comprising as a main component a conjugated diene monomer unit having 5 or more carbon atoms at an end.