Radio observations are essential for diagnosing plasma across the solar atmosphere, inner heliosphere, and Earth’s ionosphere. Key applications include: (1) radio spectroscopic imaging to diagnose nonthermal electrons and coronal magnetic fields; (2) scintillation and Faraday rotation measurements to constrain solar wind turbulence and magnetic structure; and (3) radar, radio sounding, and GPS techniques to probe plasma structure and dynamics in Earth’s upper atmosphere. Beyond advancing our understanding of fundamental plasma processes such as magnetic reconnection and particle acceleration, these tools are becoming increasingly important for improving space weather monitoring, forecasting, and response. Yet their full potential, especially through integration across domains, remains largely untapped. This session brings together researchers using radio techniques to share results, discuss new methods, and explore cross-domain data and approaches for more comprehensive space plasma and space weather research.