In this communication, a novel tightly coupled dual-polarized reflectarray antenna is presented. The antenna consists of a dual-polarized feed antenna and a wideband dual-polarized reflecting surface. The reflecting surface is composed of dual-polarized tightly coupled unit cells. Each unit cell contains two types of elements, of which the polarizations are perpendicular. Each element contains a dipole and a delay line. For one polarization, the reflecting surface consists of 13 × 34 elements, while there are 26 × 11 elements on the reflecting surface for the other polarization. The feed antenna is a wideband dual-polarized horn antenna. The phase error distribution on the reflecting surface is analyzed as well. To verify the design, a prototypical tightly coupled dual-polarized reflectarray antenna operating from 3 to 8 GHz is simulated, manufactured, and measured. The simulated results are in good agreement with the measured results. In the working band, the radiation patterns of the proposed reflectarray antenna are stable.