In order to keep pace with the growing research and development on millimetre-wave (MMW) antennas for the fifth generation (5G) networks, this paper integrates the frequency reconfigurability in a flexible antenna operating at MMW frequency spectrum. The proposed antenna is designed on liquid crystal polymer (LCP) substrate which is currently well recognised for its distinguishing performance at high frequencies. Antenna geometry consists of a radiating patch like a shape of tuning fork and two stubs which can be made part of radiating element by means of two switches. The proposed antenna offers a frequency reconfiguration over an operational frequency range of 20.7-36 GHz by four different switch configurations. Surface mount PIN diodes have been assembled on LCP substrate as a switch. Inkjet printing has also been suggested for antenna fabrication. The proposed antenna is well suited for wearable communication systems and body-centric applications for future 5G networks because of its notable features of conformity, light-weight, high-efficiency, and frequency reconfigurability.