According to one embodiment, a positive electrode is provided. The positive electrode includes a positive electrode current collector, a positive electrode active material-containing layer provided on the positive electrode current collector, and a porous layer provided on at least a part of the positive electrode active material-containing layer and containing inorganic particles. A thickness of the porous layer is 3.0 um or less. A ratio X/Y, between a mode diameter X in a log differential pore volume distribution curve obtained by mercury porosimetry with respect to the positive electrode active material-containing layer and the porous layer, and a mode diameter Y in a log differential pore volume distribution curve obtained by mercury porosimetry with respect to the positive electrode active material-containing layer, satisfies the following Equation 1: 1.0 X/Y 1.5