Gustav Robert Kirchhoff (12 March 1824 – 17 October 1887) is a German physicist who contributes to the fundamental understanding of electrical circuits, spectroscopy, and the emission of black-body radiation by heated objects.
He coins the term "black body" radiation in 1862, and two sets of independent concepts in both circuit theory and thermal emission are named "Kirchhoff's laws" after him, as well as a law of thermochemistry.
The Bunsen–Kirchhoff Award for spectroscopy is named after him and his colleague, Robert Bunsen.