In this study, a novel ultra-wideband aperture-coupled patch antenna using a comb-shaped metasurface (MS) was investigated for millimeter wave applications. The proposed antenna was fabricated with 4 layers of PCB and can be realized based on two parts, an aperture coupling feeding network, and a radiator. The coupling feeding network comprises a microstrip line with a radial stub and a coupling aperture (slot line). The radiator is a combination of a driven patch and a comb-shaped MS, which are made of uniform 4 × 4 metallic patch cells. The driven patch is used to provide good coupling performance that conveys the current to be distributed on the comb-shaped MS. The comb-shaped MS also functions as a wideband radiator that enhances the impedance bandwidth. To validate the design, a prototype operating on 28 GHz to 56 GHz was fabricated and measured. The simulated and measured results are in reasonable agreement. The prototype antenna with dimensions of 0.45 λ0× 0.45 λ0× 0.16λ0has a 10 dB impedance bandwidth of 65%, and a gain range of 5-8 dBi.