Robert Wilhelm Eberhard Bunsen (30 March 1811^[N1] – 16 August 1899) was a German chemist. He investigated emission spectra of heated elements, and discovered caesium (in 1860) and rubidium (in 1861) with Gustav Kirchhoff. Bunsen developed several gas-analytical methods, was a pioneer in photochemistry, and did early work in the field of organoarsenic chemistry. With his laboratory assistant, Peter Desaga, he developed the Bunsen burner, an improvement on the laboratory burners then in use. The Bunsen–Kirchhoff Award for spectroscopy is named after Bunsen and Kirchhoff.

Robert Bunsen was born at Göttingen in 1811 in what is now the state of Lower Saxony in Germany, but was then the short-lived Kingdom of Westphalia; upon the defeat of Napoleon three years later it became the Kingdom of Hanover. Robert was the youngest of four sons of the University of Göttingen's chief librarian and professor of modern philology, Christian Bunsen (1770–1837).Sources disagree on Robert Bunsen's exact birth date. His parish register, as well as two curricula vitae, handwritten by Bunsen himself, support the claim that 30 March 1811 is Bunsen's true birth date; however, many later sources cite 31 March as the date. According to his biographer Georg Lockemann, Bunsen himself celebrated his birthday on the 31st in his later years. Lockemann nevertheless regarded the 30th as the correct date.