This paper proposes a frequency selective surface (FSS) design to be used in Wi-Fi shielding applications as either a band reject or band pass dual-band single-layer filter. The proposed design consists of a combination of basic elements, i.e. ring loops/slots, and is tuned at both 2.4 and 5.2 GHz Wi-Fi frequency bands. It has a relatively stable frequency response in the aforementioned Wi-Fi bands for incidence angles ranging from 0º to 45º. Both band reject and band pass designs are presented, along with their unit cell dimensions. Simulation and model validation through measurements demonstrate the performance of the proposed FSS design. Active variants are also proposed and briefly evaluated, in simulation environment, which should allow for applications where an on-off switching is desired at 2.4 and 5.2 GHz Wi-Fi bands.