Hieronymus Bock (Latinised Tragus) (1498 – February 21, 1554) was a German botanist, physician, and Lutheran minister who began the transition from medieval botany to the modern scientific worldview by arranging plants by their relation or resemblance.

Hieronymus Bock, known by the German and Graeco-Latin versions of his name, Jerome Bock or Hieronymus Tragus, issued his early works under the name Hieronymus Herbarius. He, Leonhart Fuchs, and Otto Brunfels are considered the German "Fathers of Botany."

The details of his life are sketchy, in particular his educational background is unknown. In 1519 he inscribed at the university of Heidelberg. He married Eva Victor in 1523, and was schoolteacher and caretaker of the grounds of the Count Palatine in Zweibrücken for nine years.

He is the author of an important herbal, the Kraeuterbuch (1539), which is one of the first attempts to classify plants in a systematic manner according to their form. He became a follower of Martin Luther and eventually a Lutheran minister, which was the cause of him leaving Hornbach in 1548. Philipp II of Nassau gave him some refuge. In 1532 he became the prince's physician and later received a life-time position as a Lutheran minister in a nearby town where he stayed up to his death in 1554.

The first edition of his Kreuterbuch (literally "plant book") appeared in 1539 unillustrated; his stated objectives were to describe German plants, including their names, characteristics, and medical uses. Instead of following Dioscorides as was traditional, he developed his own system to classify 700 plants. Bock apparently traveled widely through the German region observing the plants for himself, since he includes ecological and distributional observations.

His 1546 The New Kreuterbuch was illustrated by the artist David Kandel. In the wine world, Bock is noted for having the first documented use of the modern word Riesling in 1552 when it was mentioned in his Latin herbal. The grass genus Tragus and spurge genus Tragia are both named after him.

The Kreuterbuch is a landmark in the field of botany. Bock is lauded for his careful study of regional plants, the quality of his plant descriptions, the clarity of his descriptions, and his discovery of plants never before described by anyone. Botanist Edward Lee Greene judges Bock to be "the first father of phytography after Theophrastus"