Tiberius Hemsterhuis (January 9, 1685 - April 7, 1766), Dutch philologist and critic, was born at Groningen in Holland.

His father, a learned physician, gave him so good an early education that, when he entered the university of his native town in his fifteenth year, he speedily proved himself to be the best student of mathematics. After a year or two at Groningen. he was attracted to the university of Leiden by the fame of Perizonius; and while there he was entrusted with the duty of arranging the manuscripts in the library. Though he accepted an appointment as professor of mathematics and philosophy at Amsterdam in his twentieth year, he had already directed his attention to the study of the ancient languages.

In 1706 he completed the edition of Pollux's Onomasticon begun by Lederlin; but the praise he received from his countrymen was more than counterbalanced by two letters of criticism from Bentley, which mortified him so keenly that for two months he refused to open a Greek book. In 1717 Hemsterhuis was appointed professor of Greek at Franeker, but he did not enter on his duties there till 1720. In 1738 he became professor of national history also. Two years afterwards he was called to teach the same subjects at Leiden, where he died on the 7th April 1766. Hemsterhuis was the founder of a laborious but useful Dutch school of criticism, which had famous disciples in Valckenaer, Lennep and Ruhnken.

His chief writings are the following:

• Luciani colloquia et Timon (1708)
• Aristophanis Plutus (1744)
• Notae, etc., ad Xenophontem Ephesium in the Miscellanea critica of Amsterdam, vols. iii. and iv.
• Observationes ad Chrysostomi homilias (1784)
• Orationes (1784)
• a Latin translation of the Birds of Aristophanes, in Kuster's edition
• notes to Bernard's Thomas Magister, to Alberti's Hesychius, to Ernesti's Callimachus and to Burmann's Propertius.

See Elogium T. Hemsterhusii (with Bentley's letters) by Ruhnken (1789), and Supplementa annotationis ad elogium T. Hemsterhusii, etc. (Leiden, 1874); also JE Sandys's Hist. Class. Scholarship, ii. (1908).