Magnetoelectric (ME) microelectromechanical and nanoelectromechanical systems (M/NEMS) offer transformative potential for the Internet of Things (IoT) by addressing critical challenges in size, energy efficiency, communication, and environmental adaptability. ME M/NEMS enable ultra-compact devices with multifunctionality, such as simultaneous sensing, data transmission, and wireless power transfer. These systems leverage ME materials and composites, which allow for electrical control of magnetism, enabling magnetoelectric, spin-orbit-coupled logic devices, and ME random access memories for attojoule-class nonvolatile information storage. ME M/NEMS also support ultra-compact antennas with improved efficiency for simultaneous wireless information and power transfer and smart sensor nodes with reduced cost, size, weight, and power compared to conventional electrical counterparts. ME materials and composites, such as piezoelectric and magnetostrictive laminates, exhibit strong ME coupling, enabling applications in magnetic field sensing, wireless power transfer, and communication systems. ME-based magnetometers can detect magnetic fields as low as fT at room temperature and are well-suited for biomedical applications. ME antennas, based on layered ME piezoelectric-magnetostrictive heterostructures, operate at their electromechanical resonance, resulting in dimensions comparable to mechanical or acoustic wavelengths, which are five orders of magnitude smaller than electromagnetic wavelengths. ME antennas are immune to the platform effect and exhibit enhanced radiation on a ground plane. ME WPT systems enable efficient wireless power transfer, with ME receivers achieving efficiencies over 80%, comparable to or exceeding resonant coil-to-coil inductive WPT links. ME antennas are also used for energy harvesting from mechanical vibrations and magnetic fields, making them suitable for bioimplant applications. ME-tunable components, such as inductors, filters, phase shifters, and resonators, offer compact, power-efficient, and tunable solutions for RF and microwave electronics. ME-based devices demonstrate high performance in data communication and WPT, enabling ultra-compact passive IoT devices for simultaneous wireless information and power transfer. Overall, ME M/NEMS show great potential for high-gain ME antennas, ultra-sensitive ME sensors, and efficient communication systems in challenging environments.Magnetoelectric (ME) microelectromechanical and nanoelectromechanical systems (M/NEMS) offer transformative potential for the Internet of Things (IoT) by addressing critical challenges in size, energy efficiency, communication, and environmental adaptability. ME M/NEMS enable ultra-compact devices with multifunctionality, such as simultaneous sensing, data transmission, and wireless power transfer. These systems leverage ME materials and composites, which allow for electrical control of magnetism, enabling magnetoelectric, spin-orbit-coupled logic devices, and ME random access memories for attojoule-class nonvolatile information storage. ME M/NEMS also support ultra-compact antennas with improved efficiency for simultaneous wireless information and power transfer and smart sensor nodes with reduced cost, size, weight, and power compared to conventional electrical counterparts. ME materials and composites, such as piezoelectric and magnetostrictive laminates, exhibit strong ME coupling, enabling applications in magnetic field sensing, wireless power transfer, and communication systems. ME-based magnetometers can detect magnetic fields as low as fT at room temperature and are well-suited for biomedical applications. ME antennas, based on layered ME piezoelectric-magnetostrictive heterostructures, operate at their electromechanical resonance, resulting in dimensions comparable to mechanical or acoustic wavelengths, which are five orders of magnitude smaller than electromagnetic wavelengths. ME antennas are immune to the platform effect and exhibit enhanced radiation on a ground plane. ME WPT systems enable efficient wireless power transfer, with ME receivers achieving efficiencies over 80%, comparable to or exceeding resonant coil-to-coil inductive WPT links. ME antennas are also used for energy harvesting from mechanical vibrations and magnetic fields, making them suitable for bioimplant applications. ME-tunable components, such as inductors, filters, phase shifters, and resonators, offer compact, power-efficient, and tunable solutions for RF and microwave electronics. ME-based devices demonstrate high performance in data communication and WPT, enabling ultra-compact passive IoT devices for simultaneous wireless information and power transfer. Overall, ME M/NEMS show great potential for high-gain ME antennas, ultra-sensitive ME sensors, and efficient communication systems in challenging environments.