The present invention provides an all-solid-state battery composition that is excellent in dispersibility of an active material or an electrolyte and adhesion, can provide a high-strength coating film or molded body, and enables the production of a high-capacity all-solid-state battery with low electrode resistance, and also provides an all-solid-state battery including the all-solid-state battery composition. The present invention relates to an all-solid-state battery composition to be used for an all-solid-state battery, the composition containing: an active material and/or a solid electrolyte; a polyvinyl acetal resin; and an organic solvent, the polyvinyl acetal resin having an average degree of polymerization of 5,000 or greater and 10,000 or less.