In this paper, a novel miniaturized and flexible dual band frequency selective surface (FSS) is presented. This FSS provides effective shielding in X-band and Ku-band, with a frequency response of 9.4 and 16.7 GHz, respectively. The proposed FSS provides 924 MHz bandwidth at X-band and 1.34 GHz bandwidth at Ku-band with an insertion loss of 20 dB. Moreover, the proposed design is polarization-independent and it provides stable frequency response at various angles of incidences for both transverse electric and transverse magnetic modes. More significantly, the proposed FSS analyzed the bandstop response of the selective frequency and also is suitable for conformal applications. A prototype of the proposed FSS is fabricated. The measured results and simulated results are good in agreement. © 2020 The Author(s). Published by Cambridge University Press in association with the European Microwave Association.