With the development of the Internet of Things (IoT), the demand for thin and wearable electronic devices is growing quickly. The essential part of the IoT is communication between devices, which requires radio-frequency (RF) antennas. Metals are widely used for antennas; however, their bulkiness limits the fabrication of thin, lightweight, and flexible antennas. Recently, nanomaterials such as graphene, carbon nanotubes, and conductive polymers came into play. However, poor conductivity limits their use. We show RF devices for wireless communication based on metallic two-dimensional (2D) titanium carbide (MXene) prepared by a single-step spray coating. We fabricated a ~100-nm-thick translucent MXene antenna with a reflection coefficient of less than -10 dB. By increasing the antenna thickness to 8 μm, we achieved a reflection coefficient of -65 dB. We also fabricated a 1-μm-thick MXene RF identification device tag reaching a reading distance of 8 m at 860 MHz. Our finding shows that 2D titanium carbide MXene operates below the skin depth of copper or other metals as well as offers an opportunity to produce transparent antennas. Being the most conductive, as well as water-dispersible, among solution-processed 2D materials, MXenes open new avenues for manufacturing various classes of RF and other portable, flexible, and wearable electronic devices.