Atomically thin two-dimensional materials—including transitional metal dichalcogenides and hexagonal boron nitride—can exhibit non-volatile resistive switching. This switching behaviour could be used to create analogue switches for use in high-frequency communication, but has so far been limited to frequencies relevant to the fifth generation of wireless communication technology. Here we show that non-volatile switches made from monolayer molybdenum disulfide in a metal–insulator–metal structure can operate at frequencies corresponding to the sixth-generation communication band (around 100–500 GHz). The switches exhibit low insertion loss in the ON state and high isolation in the OFF state up to 480 GHz with sub-nanosecond pulse switching. We obtain the eye diagrams and constellation diagrams at various data transmission rates and modulations to evaluate the device performance, including real-time data communication up to 100 Gbit s⁻¹ at a carrier frequency of 320 GHz, with a low bit error rate and high signal-to-noise ratio.