St Thomas's Abbey, Brno

The Augustinian Abbey of St Thomas, Brno
Abbey church of the Assumption
The south entrance of the church

St Thomas's Abbey (or the Königskloster) (Czech: Starobrněnský klášter) is an Augustinian abbey and church located in Brno in the Czech Republic. The geneticist and abbot Gregor Mendel was its most famous religious leader to date, who between 1856 and 1863 conducted his experiments on pea plants in the monastery garden. His experiments brought forth two generalizations which later became known as Mendel's Laws of Inheritance.

The Abbey is unique amongst modern Augustinian foundations because it is not called a priory, and indeed it has an abbot (Prälat - prelate) whereas all other existing Augustinian friaries are led by a prior.