The area was settled by Alamanni around the year 600.
The name also comes from this period.
In 1895, in excavations for the construction of a hotel, a graveyard of 15 graves from the seventh century, with 18 skeletons and burial objects, was discovered.

Wilderswil is first mentioned in the year 1224 as Wilderswile.
Unspunnen Castle, within the municipality, was first mentioned in 1232.

Wilderswil was governed by the barons of Rotenfluh-Wilderswil, later also by the barons of Waediswil, Weissenburg and Scharnachtal.
During the Middle Ages, the villages of Mülenen and Grenchen (now part of the municipality) were part of the Herrschaft of Weissenau Castle.
Around 1334, the Freiherr of Weissenau joined other local nobles in a war against the growing power of the city of Bern.
After the defeat of the nobles, Weissenau was forced to sell the castle and his Herrschaft to Interlaken Abbey to pay his debts.
In 1528, the city of Bern adopted the new faith of the Protestant Reformation and began imposing it on the Bernese Oberland.
The Abbey and its villages, including Mülenen and Grenchen, joined in an unsuccessful rebellion against the new faith.
After Bern imposed its will on the Oberland, they secularized the Abbey and annexed all the Abbey lands.
The two villages became a part of the Bernese bailiwick of Interlaken.
 During the 15th century, the alpine village of Gsteigallmend was built above the village of Grenchen.
In the following century, Grenchen was gradually abandoned.

Wilderswil village was part of the Herrschaft of Unspunnen and had a history different from the other two villages.
It remained under Unspunnen until the late 15th century.
Between 1488 and 1515, the city of Bern gradually acquired rights and land in Unspunnen until they owned the entire Herrschaft.
Under Bernese rule, Wilderswil was incorporated into the municipality of Unterseen, where it remained until 1798.

Since 1805, the Unspunnenfest, a festival that highlights traditional Swiss culture, has been held at regular intervals in the grounds of the now-ruined, Unspunnen Castle.

The tourism industry began in Wilderswil in the 19th century with the construction of a road from Interlaken to the Lütschine river valleys.
The Bernese Oberland Railway built a station in the municipality in 1890, followed by the base station of a funicular railway to the Schynige Platte two years later.
These easy transportation links encouraged the construction of hotels and resorts.
By 1910, there were a dozen hotels in the municipality.
The tourism industry suffered during the World Wars and the Great Depression, but in 1941 the Swiss Army built an airfield in Wilderswil.
The airfield and the railroad became the largest employers in Wilderswil.
The airfield closed in 2003 and, as of 2014, is used for racing and concerts.
The area was settled by Alamanni around the year 600. The name also comes from this period. In 1895, in excavations for the construction of a hotel, a graveyard of 15 graves from the seventh century, with 18 skeletons and burial objects, was discovered.
Wilderswil is first mentioned in the year 1224 as Wilderswile. Unspunnen Castle, within the municipality, was first mentioned in 1232.
Wilderswil was governed by the barons of Rotenfluh-Wilderswil, later also by the barons of Waediswil, Weissenburg and Scharnachtal. During the Middle Ages, the villages of Mülenen and Grenchen (now part of the municipality) were part of the Herrschaft of Weissenau Castle. Around 1334, the Freiherr of Weissenau joined other local nobles in a war against the growing power of the city of Bern. After the defeat of the nobles, Weissenau was forced to sell the castle and his Herrschaft to Interlaken Abbey to pay his debts. In 1528, the city of Bern adopted the new faith of the Protestant Reformation and began imposing it on the Bernese Oberland. The Abbey and its villages, including Mülenen and Grenchen, joined in an unsuccessful rebellion against the new faith. After Bern imposed its will on the Oberland, they secularized the Abbey and annexed all the Abbey lands. The two villages became a part of the Bernese bailiwick of Interlaken.  During the 15th century, the alpine village of Gsteigallmend was built above the village of Grenchen. In the following century, Grenchen was gradually abandoned.
Wilderswil village was part of the Herrschaft of Unspunnen and had a history different from the other two villages. It remained under Unspunnen until the late 15th century. Between 1488 and 1515, the city of Bern gradually acquired rights and land in Unspunnen until they owned the entire Herrschaft. Under Bernese rule, Wilderswil was incorporated into the municipality of Unterseen, where it remained until 1798.
Since 1805, the Unspunnenfest, a festival that highlights traditional Swiss culture, has been held at regular intervals in the grounds of the now-ruined, Unspunnen Castle.
The tourism industry began in Wilderswil in the 19th century with the construction of a road from Interlaken to the Lütschine river valleys. The Bernese Oberland Railway built a station in the municipality in 1890, followed by the base station of a funicular railway to the Schynige Platte two years later. These easy transportation links encouraged the construction of hotels and resorts. By 1910, there were a dozen hotels in the municipality. The tourism industry suffered during the World Wars and the Great Depression, but in 1941 the Swiss Army built an airfield in Wilderswil. The airfield and the railroad became the largest employers in Wilderswil. The airfield closed in 2003 and, as of 2014, is used for racing and concerts.
Wilderswil