Wildenburg Castle (German: Burg Wildenburg) is a ruined castle near Kempfeld in the county of Birkenfeld in the German state of Rhineland-Palatinate.
The predecessor of the Wildenburg was probably a Celtic refuge fort with double ramparts from the La Tène period (ca. 450-50 B.C.). The Wildenburg rampart is one of a number of Celtic fortifications in southern Hunsrück between the hillfort of Otzenhausen, the Ringkopf, the Altburg and the Alteburg in Soonwaldsteig. A short section of the rampart has been reconstructed as a "Gallic Wall" (murus gallicus).
Around the year 350 A. D. a late Roman fort was established on the Wildenburg for a short time.
In the Late Middle Ages Wildenburg was built by the Wildgrafen family on the rocks at the western tip of the circular rampart. It was first mentioned in 1330 and was pillaged and destroyed by marauding troops from Lorraine in 1651. After being partially rebuilt in 1660, the lower ward of the castle acted as the administrative headquarters for the Amt of Wildenburg until the abolition of the county in the 1792.