In the present work, investigation of thermoelectric properties of pure indium tin oxide (ITO) and indium tin oxide with 2 at.% tin (Sn) samples was carried out using a vacuum hot press (VHP). Temperature (T) dependence of thermoelectric (TE) properties of indium tin oxide and indium tin oxide with 2 at.% tin samples has been studied within the temperature range of 300 K to 800 K. It is observed that the indium tin oxide with 2 at.% tin sample has a lower electrical resistivity i.e.9.12 μΩ-m at 800 K compared to the pristine sample having 12.73μΩ-m at 800K. The seebeck coefficient of indium tin oxide 2 at.% tin sample and pure ITO sample are -37.9 μV/K at 800 K and -35.1 μV/K at 800K respectively. Hence the power factor of the indium tin oxide with 2 at% tin sample has 1.6 times higher value compared with the pristine. This reduction in electrical resistivity in ITO with 2 at.% Sn sample is attributed by the liquid phase compaction due to liquid tin which improved contact between the grains but at the same time results into the formation of dislocation array at the grain boundaries due to the liquid metallic tin. These dislocation arrays help to improve seebeck coefficient by way of energy filtering effect.