Radically novel approaches will be needed to support the 1,000 times increase in data rates expected from next-generation wireless communications (5G). Integrated microwave photonics (IMWP) techniques have been identified as an enabling technology for 5G, as they have the potential to improve the performance of electronics by leveraging the broadband characteristics and flexibility of operation of photonic integrated circuits. Important applications of IMWP are optical signal generation and distribution of mm-waves towards antenna terminals, frequency-reconfigurable filtering, optical control of antenna arrays, and more. The rapidly growing field of plasmonics has shown a breakthrough in performance for optical modulators with ultra-fast operation (>170 GHz) and ultra-compact footprint (10s µm²). This paper reports recent achievements on the use of integrated plasmonic devices for millimeter-wave signal conversion and processing for next-generation wireless systems.