A honeycomb structure includes: a honeycomb structure body which includes a porous partition wall defining a plurality of cells extending from an inflow end face to an outflow end face; an inflow side plugging portion; and an outflow side plugging portion, in which the plurality of cells includes an outflow cell having a quadrangle shape in a cross-section, an inflow cell having a pentagonal or hexagonal shape in a cross-section and being formed adjacently around the outflow cell with the partition wall defining the outflow cell while surrounding the outflow cell interposed therebetween, and in a cross-section orthogonal to the extension direction of the cell, a value of a ratio of a distance Y with respect to a distance X is 1.1 to 1.8.