In the present work, investigation of conjugate cooling of an obstacle mounted in a parallel-plate channel is carried out with the aid of the lattice Boltzmann simulation of a laminar incompressible fluid flow and heat transfer. The aim is to develop the lattice Boltzmann conjugate heat transfer formulation, based on on-lattice scheme, at the solid−fluid interfaces for incompressible flows by conducting studies of various cases ,including methods of heating different obstacles. In this way, the effects of the pertinent parameters such as the Reynolds number and solid-to-fluid thermal conductivity ratios on the local Nusselt number around the obstacle periphery are investigated. The results of the present study are compared with those obtained by conventional numerical methods, and good agreement is observed.