According to one embodiment, a solid electrolyte secondary battery includes a positive electrode containing an active material, a negative electrode containing an active material, and a solid electrolyte layer. The solid electrolyte layer includes a lithium-ion conductive sulfide containing at least one element selected from a group consisting of Al, Si, Fe, Ni, and Zr, the total content of the element in the lithium-ion conductive sulfide is 0.03% by mass or more and 0.3% by mass or less.