German biblical critic and an important figure in Hebrew and other Semitic language studies.

Educated at Helmstedt and at Göttingen, in 1811 Gesenius became professor of theology at Halle. Though accused of rationalism, he was never dismissed from his post. He published little that was controversial; his chief theological publication was a commentary on Isaiah (1821–29). Gesenius inaugurated in Semitic language studies a modern philological approach such as had been developed in Indo-Germanic linguistics. His Hebrew grammar (1813; edited and enlarged by E. Kautzsch; 2nd English edition revised according to the 28th German edition by A.E. Cowley, 1910) and his Hebrew and Chaldee (i.e., Aramaic) dictionary (1810–13; Eng. trans., 1959) taught generations of scholars, and have been kept alive into the second half of the 20th century in various editions and translations. Gesenius also laid the basis for Semitic epigraphy, collecting and deciphering the Phoenician inscriptions known in his time.