The Old University of Leuven (or of Louvain) is the name historians give to the university, or studium generale, founded in Leuven, Brabant (then part of the Burgundian Netherlands, now part of Belgium), in 1425. The university was closed in 1797, a week after the cession to the French Republic of the Austrian Netherlands and the principality of Liège (jointly the future Belgium) by the Treaty of Campo Formio.

The name was in medieval Latin Studium generale Lovaniense or Universitas Studii Lovaniensis, in humanistical Latin Academia Lovaniensis, and most usually, Universitas Lovaniensis, in Dutch Universiteyt Loven and also Hooge School van Loven.It is commonly referred to as the University of Leuven or University of Louvain, sometimes with the qualification "old" to distinguish it from the Catholic University of Leuven (established 1835 in Leuven). This might also refer to a short-lived but historically important State University of Leuven, 1817–1835. The immediate official and legal successor and inheritor of the old University, under the laws in force in 1797, was the École centrale de Bruxelles, which itself closed down in 1802.