A thermoplastic elastomer composition includes: at least one elastomer component selected from the group consisting of elastomeric polymers each of which has a side chain containing a hydrogen-bond cross-linkable moiety having a carbonyl-containing group and/or a nitrogen-containing heterocycle and has a glass-transition point of 25° C. or below, and elastomeric polymers each of which contains a hydrogen-bond cross-linkable moiety and a covalent-bond cross-linking moiety in a side chain and has a glass-transition point of 25° C. or below; a clay, a content ratio of which is 20 parts by mass or less relative to 100 parts by mass of the elastomer component; and an α-olefin-based resin having no chemical-bond cross-linking moiety.