The thermal behavior of iron nanoclusters on a porous substrate has been studied using classical molecular dynamics simulations. The substrate has been modeled with a simple Morse potential and pores with different shapes have been modeled in order to mimic the porous substrates used for carbon nanotube growth. It has been confirmed that the presence of the substrate increases the cluster melting temperature compared to the free cluster. In addition, the magnitude of this increase in melting point depends on the existence, shape, and diameter of the pore. For example, the increase in melting point is larger for clusters supported on flat (nonporous) substrates than for clusters which straddle pores with smaller diameters than the cluster diameter.