The present research deals with steady free convection heat transfer in a differentially heated square enclosure filled with air with an interior heat generating conducting solid circular cylinder at different diagonal locations. The purpose of the present study is to examine how the location of the interior cylinder and its heat generation affect on the free convection phenomena for various Rayleigh numbers when an interior cylinder moves at various locations along the diagonal of the outer square enclosure. The steady governing equations are solved numerically by using the finite volume approach..The present work results explain that increase in the heat generation and Rayleigh numbers have a clear effect on the stream and isotherm contours. While, the interior cylinder locations does not play an important role when the interior cylinder does not generate heat. Also, the results show that the average Nusselt number at the hot side wall decreases for all values of (?) when the heat generation value increases, while the average Nusselt number at the cold side wall increases for all values of (?) when the heat generation value and Rayleigh number increases. A comparison of the results showed a good agreement with another published results.