In this paper, the unsteady magnetohydrodynamic (MHD)-radiation-natural convection of a hybrid nanofluid within a U-shaped wavy porous cavity is investigated. This problem has relevant applications in optimizing thermal managementsystemsinelectronic devices, solar energy collectors, and other industrial applications where efficient heat transfer is very important. The study is based on the application of a numerical approach using the Finite Difference Method (FDM) for the resolution of the governing equations, which incorporates the Rosseland approximation for thermal radiation and the Darcy-Brinkman-Forchheimer model for porous media. It was found that the increase of Hartmann number (Ha) causes a reduction of the average Nusselt number (Nu), with a maximum decrease of 25% observed as Ha increases from 0 to 50. In addition, the influence of the wall’s wave amplitude and the heat source length on the heat transfer rate was quantified, and it was revealed that at high wave amplitude, the average Nu increases by up to 15%. These findings suggest that manipulating magnetic field strength and cavity geometry can significantly enhance thermal performance. The novelty of this is related to the exploration of a U-shaped wavy cavity, which is not covered in previous studies, and to the detailed examination of the combined effects of magnetic fields, radiation, and hybrid nanofluids.