A dual-polarized antenna and a dual-polarized antenna assembly including the same are provided. A dual-polarized antenna includes a base board, feeding unit supported on the base board, and radiation plate supported on the feeding unit. The feeding unit includes a first and a second feeding boards arranged to cross each other on the base board. The first feeding board includes a first feed line configured to supply a first reference-phase signal to a first point on the radiation plate and supply a first antiphase signal having an antiphase relative to the first reference-phase signal to a second point on the radiation plate. The second feeding board includes a second feed line configured to supply a second reference-phase signal to a third point on the radiation plate and supply a second antiphase signal having an antiphase relative to the second reference-phase signal to a fourth point on the radiation plate.