The objective of one or more embodiments of the present invention is to provide a zirconia electrolyte which has high strength and which is suitable for a solid electrolyte layer of a solid oxide fuel cell, and a method for producing a zirconia electrolyte having high strength. The zirconia electrolyte according to one or more embodiments of the present invention is characterized in essentially consisting of zirconia stabilized by one or a plurality of oxides of rare earth selected from the group of scandium, yttrium, cerium, gadolinium and ytterbium, wherein a standard deviation of pore numbers in 10 or more regions having an area of 50 μm2 and not overlapping with each other on a fracture surface is 2.5 or more.