Doped and partially-reduced oxide (e.g., SrTiO3-based) thermoelectric materials. The thermoelectric materials can be single-doped or multi-doped (e.g., co-doped) and display a thermoelectric figure of merit (ZT) of 0.2 or higher at 1050 K. Methods of forming the thermoelectric materials involve combining and reacting suitable raw materials and heating them in a graphite environment to at least partially reduce the resulting oxide. Optionally, a reducing agent such as lanthanum boride, titanium carbide, titanium nitride, or titanium boride can be incorporated into the starting materials prior to the reducing step in graphite. The reaction product can be sintered to form a dense thermoelectric material.