Seebeck was born into a wealthy family in Tallinn, the Estonian capital, and moved to Germany at the age of 17. He studied medicine in Berlin and in 1802 received an MD from the University of Göttingen. More interested in science than medical practice, he was wealthy enough to be able to devote his time to scientific research. In the early years of the 19th century he moved to Jena, where he became acquainted with an important intellectual circle of scientists and philosophers. His subsequent researches made him one of the most distinguished experimental physicists of his day.

Seebeck made investigations into photoluminescence (the luminescent emission from certain materials excited by light), the heating and chemical effects of different parts of the solar spectrum, polarization, and the magnetic character of electric currents. His most important work however came in 1822, after he had moved to Berlin. His discovery of thermoelectricity (the Seebeck effect) showed that electric currents could be produced by temperature differences. Seebeck joined two wires of different metals to form a closed circuit and applied heat to one of the junctions; a nearby magnetic needle behaved as if an electric current flowed around the circuit. He called this effect ‘thermomagnetism’ (and later objected to the term thermoelectricity).