Indium tin oxide (ITO) ceramics with different SnO2 contents were fabricated using the conventional solid-state reaction. The phase structure, microstructure, electrical conductivity, heating, and mechanical properties were investigated in detail. The results showed that pure ITO ceramics with high relative density were obtained successfully. The ITO ceramics were cut into regular rectangles to serve as electrical heaters. Additionally, their saturation temperatures and thermal response times were tested at different voltages. The results showed that ITO ceramics with 10% SnO2 had the fastest thermal response rate and reached a saturation temperature of 376∘C at 1.5[Formula: see text]V voltage, the highest temperature reported in the literature for In2O3 ceramics. Moreover, In2O3 with 10% SnO2 showed good mechanical properties. Hence, ITO ceramics, as electrical heaters with low driving voltage and high response speed, are expected to have potential heating applications such as domestic heating and industrial production.