Pfaffenberg, Mountain summit in Döbling district, Vienna, Austria

Pfaffenberg is a mountain in the northern Wienerwald range, rising to about 415 meters and forming part of the landscape in Vienna's Döbling district. Its slopes are covered with forest and traversed by several established paths that connect different sections of the wooded area.

Pfaffenberg was first documented in 1340 as "ze Obern Sufrigen an dem Pfaffenberge", a reference to its location in Obersievering; the name comes from the Old High German word Pfaffe. In 1784 Hofrat Binder von Krieglstein acquired the Himmel estate on the mountain and had a small castle built there; his successor laid out a park later used for agriculture. From 1854 to 1856 the merchant Johann Carl Freiherr von Sothen built the Sisi-Kapelle on the southern slope.

The name Pfaffenberg comes from the Old High German word Pfaffe, meaning priest, and the hill was first recorded in 1340 as lying in Obersievering. At Am Himmel, a former estate and inn, a circle of forty trees was planted in 1997, each with a signboard describing its place in the so-called Celtic tree horoscope. Nearby stands the Oktogon am Himmel, an octagonal wooden hut with glass fronts housing a small restaurant facing the city.

Several hiking trails of varying difficulty lead up the mountain, making it accessible to different levels of experience and fitness. The area is easily reached by public transportation, which serves the Döbling district well.

The wooded summit is called Pfaffenkogel in older usage, and the name Pfaffenberg comes from the Old High German word Pfaffe, meaning priest. The first written record, from 1340, places it in Obersievering. The hill belongs to the Flysch zone, built of sandstone, marl and claystone rather than limestone.