A numerical study is conducted to investigate unsteady, two-dimensional mixed convection in a lid-driven cavity containing deformable bodies. The cavity features moving top and left walls, while internal heat-generating obstacles are modeled as elastic bodies of elliptic, circular, and rectangular shapes. The interaction of obstacle geometry, lid motion, and thermal gradients leads to complex flow and heat transfer behavior. Deformable bodies introduce fluid–structure interaction (FSI), where the coupling between fluid forces and structural deformation significantly affects the thermo-fluid dynamics. The governing dimensionless incompressible Navier–Stokes and energy equations, formulated under the Boussinesq approximation, are coupled with linear elastodynamic equations to model structural deformation. Kinematic, thermal, and dynamic continuity conditions are imposed at the fluid–structure interface. The resulting nonlinear FSI system is solved using a local radial basis function (RBF)-based meshfree method, which efficiently handles complex and deforming geometries without mesh connectivity. This study demonstrates the capability and robustness of meshfree techniques for mixed convection problems involving deformable internal bodies.