This article proposes a low profile and miniaturized ultra-wideband frequency selective surface (UWB FSS) structure which provides wide bandwidth for shielding applications. A single layer FSS constructed with a simple square loop and cross dipole structure provides bandstop filter response covering high frequencies from 4.85 GHz to 17.23 GHz at 10 dB insertion loss, with a bandwidth of 12.38 GHz and a fractional bandwidth exceeding 112%. The proposed FSS structure also provides excellent polarization independent behavior for angles of incidence up to 30°. A prototype of the proposed FSS is fabricated and the measurement result is compared with the simulation results, and both are in good agreement. © 2020, The Minerals, Metals & Materials Society.