Fittig was born in Hamburg and gained his doctorate at Göttingen in 1858, becoming a professor at Tübingen (1870) and at Strasbourg (1876–1902). He was a prolific experimentalist with many discoveries and syntheses to his credit, including pinacol, diphenyl, mesitylene, cymene, coumarone, and phenanthrene in coal tar. He also did extensive work on lactones and unsaturated acids. His name is remembered in the Wurtz–Fittig reaction, a variation of the Wurtz reaction for synthesizing alkylaryl hydrocarbons. An example is the reaction to form methylbenzene (toluene): CH₃Cl + C₆H₅Cl + 2Na → C₂H₅CH₃ + 2NaCl