Understanding how unconventional magnetic symmetry reshapes correlation-driven metal–insulator transitions is a central problem in strongly correlated systems. Here we investigate the finite-temperature behavior of a strongly correlated $d$-wave altermagnet across the Mott metal–insulator transition using a non-perturbative numerical approach. We show that altermagnetic symmetry fundamentally reshapes the Mott transition by stabilizing a finite-temperature magnetically correlated metallic phase generated by spin-selective anisotropic hopping. Mapping the thermal phase diagram, we identify the characteristic scales governing magnetic order and Mott physics, demonstrating that altermagnetism controls the behavior of the magnetic transition scale across the interaction regimes.