The "Theory and Simulation of Solar System Plasmas" session is a forum for presenting recent results related to theoretical and numerical investigation of heliospheric plasmas. Our regions of interest are the Sun and its corona, the solar wind and planetary magnetospheres. Processes of interest are magnetic reconnection, turbulence, shock waves, plasma instabilities, plasma heating and particle acceleration. We particularly welcome studies integrating numerical modeling, theoretical investigations and in-situ measurements or remote observations from current and future space missions (MMS, Parker Solar Probe, Solar Orbiter, Bepi Colombo, ASO-S, Plasma Observatory, HelioSwarm, SMILE, SPO ...). Any modeling approach, from global to kinetic, is at home here. We particularly encourage submissions on advances in high resolution global models that reproduce mesoscale phenomena and global modeling that go beyond single fluid MHD (including global hybrid and global MHD models with embedded kinetic domains). The focus of this year's session is the interplay between global and kinetic-scale processes in heliospheric plasmas: how global drivers results into smaller scale (down to kinetic) processes, and how small scale processes in turn set constraints on global heliospheric observables.