Freudenberg is a town in the Siegen-Wittgenstein district, in North Rhine-Westphalia, Germany. The town lies on the German-Dutch holiday road called the Orange Route, joining towns, cities and regions associated with the House of Orange.

Freudenberg lies in hilly uplands between 243 and 505 m above sea level. The 17 constituent communities share roughly 55 km², of which two thirds is made up of broadleaf and spruce forest.

Besides the main town, which bears the same name as the whole municipality, there are sixteen outlying centres named Alchen, Bottenberg, Bühl, Büschergrund, Dirlenbach, Heisberg, Hohenhain, Lindenberg, Mausbach, Niederheuslingen, Niederholzklau, Niederndorf, Oberfischbach, Oberheuslingen, Oberholzklau and Plittershagen. Among these, the main town is the biggest, and the next in size after that is Büschergrund, which is itself further subdivided into four parts, named Büschen, Eichen, Anstoß and Bockseifen.

The oldest constituent communities are most likely the two that were both mentioned in documents in the 11th century, namely Plittershagen and Oberholzklau in 1079. Freudenberg is known to have been an Amt and court seat as of the early 15th century. The village and the castle of Freudenberg had their first documentary mention in 1389.

The castle was founded over the Weibe Valley together with a settlement by the Counts of Nassau as a corner post of their domain. Count Johann IV of Nassau, Vianden and Diez gave the Freudenberg townsfolk their "freedom rights" on 7 November 1456. This was a kind of minimal town rights, but the document bestowing this distinction upon the town is taken as evidence of town rights being granted Freudenberg. Documents give clues that Freudenberg was established quite early on as a "Flecken", or market town. The historic town core is even still called Alter Flecken (alt means "old"; –er is a grammatical inflection).

In 1540, both the castle and the town were heavily damaged by a fire. On William the Rich's orders, there came into being about the mid 16th century new building works. The market town was given a new town wall with four gates. In the northwest, the Hohenhainer Tor was built, in the northeast the Weihertor, in the southeast the Braastor and in the southwest the Schultor (Tor means "gate"). However, owing to yet another town fire on 9 August 1666, the town was once again laid waste. Prince Johann Moritz von Nassau-Siegen built the town anew, using much the same layout, planned in 1540, as had stood before the fire. The castle, however, was not restored, and to this day, all that can be seen of it are a few wall remains.

The charge in Freudenberg's civic coat of arms is variously interpreted as a castle or a town gate. If the later is the case, it might heraldically be described thus: In azure a crenellated town gate Or with two crenellated towers Or. In either case, the town's current arms, granted in 1911 and confirmed in 1970, are based on the town's oldest known seal, from 1473. This seal's colours were not known; the blue and gold seen today are the colours of the old princely house of Nassau-Siegen.

At the Südwestfälische Freilichtbühne Freudenberg (Freudenberg South Westphalian Open-air Stage), before a breathtaking backdrop of forest and crags, two new productions are staged every year for children and adults. Yearly, about 50,000 visitors come to the open-air stage with its roofed grandstand.

The town museum (Stadtmuseum) has exhibits relating to local history and economic history. Especially worth seeing is the House's clock collection. The Technical Museum (Technikmuseum) has on display exhibits relating to trade and industrial history from the region. The museum's centrepiece is a steam engine built in 1904. As well, the museum has a variety of wheeled vehicles on display.

The "Alter Flecken" is Freudenberg's downtown core, built wholly of half-timbered houses. It gives the impression of a small town from the 17th century. The Alter Flecken was included in the Kulturatlas des Landes Nordrhein-Westfalen (Cultural Atlas of the State of North Rhine-Westphalia) as a "Building monument of international importance". The Evangelical church, after Freudenberg got its own parish in 1585, was built as a "fortress church" (i.e. with architecture somewhat reminiscent of a military fortification). The belltower is the only one of the former castle's towers still left standing.

The church in Oberholzklau was built early in the 13th century and is worth seeing as a Romanesque church whose architecture nevertheless plainly shows transition to Gothic. The rectory next door, built in half-timbered style, is from 1608.