The optical plasmonic field has been in the spotlight for decades, the concept and applications of which have been generalized to spoof surface plasmon polaritons (also termed as the plasmonic metamaterials) in the microwave, millimeter wave, and terahertz bands. Resembling the modal profiles of optical plasmons, spoof surface plasmon polaritons at these lower frequencies present unique properties and emerging applications. This session focuses on recent progresses on the spoof surface plasmon polaritons, including fundamental physics, device designs, plasmonic antennas, and novel principles for communicating and sensing systems.