The use of a trapezoidal‐wave shaped diathermal partition to reduce natural convection flow and heat transfer within a fluid‐saturated, differentially heated porous enclosure is investigated in this study. This work is motivated by the need to control and reduce convective heat transfer in differentially heated porous enclosures, impacting applications like energy‐efficient building materials, thermal insulation, and improved heat exchangers. The study aims to disrupt convection currents and minimize thermal transfer. The Darcy flow model, representing fluid flow in porous media, is applied here and solved using the successive accelerated replacement (SAR) scheme with a finite difference method. Key parameters are varied to explore their effects on thermal and flow patterns. These parameters include the partition's length (with values between ), height (spanning from ), and distance from the left wall of the enclosure (), along with the modified Rayleigh number, which ranges from . Through computational visualization of streamlines and isotherms, this study examines how changes in partition geometry influence flow deviations. Results indicate that the trapezoidal partition allows flexibility in adjusting its geometrical parameters, effectively reducing convection flow strength without significant compromise. A drop of 41.13% in flow strength and about 56% reducted in heat transfer is achieved for trapezoidal partition with smaller edge length These findings suggest that such a partition setup can significantly improve thermal management in systems where fluid‐saturated porous enclosures are subject to differential heating.