A single-layer dual-band orthogonal polarisation reflectarray antenna composed of a combination of split cross and rectangle rings for one band and double split square rings for the other band is presented. Using these types of cell elements, a wideband, single-layer dual-band (12 GHz/14 GHz) orthogonal polarisation reflectarray is designed, fabricated, and tested. Measured results demonstrate radiation efficiency close to 60 for both bands and a 1 dB gain bandwidth of 24 for the lower band and 19 for the upper band.