Horst Lademacher (born 13 July 1931) is a German historian specializing in the history of the Netherlands.

[1] In 1957 he obtained his doctorate at the University of Münster with a dissertation titled: "Die Stellung des Prinzen von Oranien als Statthalter in den Niederlanden von 1572-1584", about the position of William of Orange as stadtholder in the Netherlands from 1572 to 1584.

[2] In 1969 Lademacher obtained his habilitation at the University of Bonn under Franz Petri [de] with a dissertation titled: "Die belgische Neutralität als Problem der europäischen Politik 1830-1914" on the Belgian neutrality as a problem of the European politics from 1830 to 1914.

[1] In 1990 he became professor of modern history at the University of Münster and director of its then newly-founded Zentrum für Niederlande-Studien.

[1] Lademacher was elected a foreign member of the Royal Netherlands Academy of Arts and Sciences in 1992.