Mixed convection heat transfer and fluid flow in an inclined square lid-driven enclosure is studied using differential quadrature (DQ) technique. Two parallel walls of the enclosure are adiabatic while one fixed wall is heated with a constant heat flux heater and moving lid is isothermal. The calculations are performed in the range of the Richardson number from 0.1 to 100. The effects of inclination angle on heat transfer and flow field are examined for 0 degrees <= phi <= 180 degrees. The distributions of streamlines and isotherms, and the variations of local and mean Nusselt numbers with the Richardson number and inclination angle are presented. The obtained results show that the inclination angle does not have a significant effect on heat transfer and fluid flow in a cavity with Ri = 0.1. The effect of the inclination angle enhances with an increase of Ri number. Almost a pure conduction heat transfer from heater wall to the moving lid is observed for a cavity with Ri = 10 and phi = 180 degrees.