Henry III of Louvain (German: Heinrich, Dutch: Hendrik, French: Henri; died 1095), was Count of Louvain (Leuven) and Landgrave of Brabant, son of Henry II (c. 1020–1078), Count of Louvain and Brussels, and Adela of Orthen (or Betuwe),[1] a daughter of Count Everard of Orthen.

He was allied by family marriages to most of the nearby lords: he was brother-in-law of Baldwin II of Hainaut, and son-in-law of Robert I of Flanders.

He supported religious foundations in the western parts, and legislated to reduce lawlessness.

After the death on 20 September 1085 of Hermann II, count palatine of Lotharingia, he became landgrave of Brabant, which was an imperial fief between the Dender and the Zenne.

Since he was succeeded by his brother Godfrey I of Leuven, it is inferred that he did not leave a son as heir.