Biberstein is a municipality in the district of Aarau of the canton of Aargau in Switzerland.

[3] The neighboring communities are Auenstein to the east, Küttigen to the west, Rohr to the south, Rupperswil to the south-east and Thalheim to the north-east.

Of the rest of the land, 10% is settled (buildings or roads) and the remainder (4.6%) is non-productive (rivers or lakes).

[5] Based on archaeologic evidence, the Biberstein area has been inhabited since at least the 6th century.

Near the castle there was also a ferry that operated between Biberstein and Rohr until the beginning of the Second World War when it was replaced with a bridge.

[6] Following the Napoleonic invasion and collapse of the Swiss Ancien Régime in 1798 Biberstein became part of the District of Aarau in the new Canton Aargau.

The blazon of the municipal coat of arms is Gules a Beaver Argent sitting on a mount of the same gnawing a piece of wood Or.

[5] The age distribution, as of 2008[update], in Biberstein is; 130 children or 9.6% of the population are between 0 and 9 years old and 111 teenagers or 8.2% are between 10 and 19.

[12] The historical population is given in the following table:[6] The village of Biberstein is designated as part of the Inventory of Swiss Heritage Sites.

[15] From the 2000 census[update], 236 or 21.4% are Roman Catholic, while 678 or 61.6% belonged to the Swiss Reformed Church.