Adolf IV (before 1205 – 8 July 1261) was a Count of Schauenburg (1225–1238) and of Holstein (1227–1238), of the House of Schaumburg.
In 1225 he won the Battle of Mölln against Albert II, Count of Weimar-Orlamünde.
On 22 July 1227 with his coalition army Adolf was victorious in the Battle of Bornhöved against King Valdemar II of Denmark with his Danish army and German allies (the Welfs), and thus regained Holstein.
[1] In fulfilment of an oath taken during the heat of the Battle of Bornhöved, Adolf withdrew in 1238 to a Franciscan friary and in 1244 was ordained a priest in Rome (his two under-age sons passed into the guardianship of his son-in-law Duke Abel of Schleswig).
He died in 1261 in the Franciscan friary in Kiel, which he himself had founded, whereupon Holstein was divided between his sons John (of Holstein-Kiel) and Gerhard (of Holstein-Itzehoe).