Wyssachen is a municipality in the Oberaargau administrative district in the Swiss canton of Bern.

In 1755 Wyssachen began to care for the local poor independently of Eriswil.

The 334 inhabitants of Neuligen and Schwendi left Wyssachen to become part of Eriswil in 1888.

[5] Originally consisting of scattered farm houses without a true village center, in the last century the village school house and surrounding buildings have become the municipal core.

On the following day, 1 January 2010, it joined the newly created Verwaltungskreis Oberaargau.

[6] The blazon of the municipal coat of arms is Gules between a Pall wavy Argent in chief a Mullet Or.

[9] Most of the population (as of 2000[update]) speaks German (1,175 or 98.1%) as their first language, Albanian is the second most common (12 or 1.0%) and French is the third (2 or 0.2%).

In 2012, single family homes made up 35.9% of the total housing in the municipality.

[14] The historical population is given in the following chart:[3][15][16] As of  2011[update], Wyssachen had an unemployment rate of 1.26%.

[9] There were 573 residents of the municipality who were employed in some capacity, of which females made up 38.4% of the workforce.

In the tertiary sector; 11 or 16.2% were in wholesale or retail sales or the repair of motor vehicles, 13 or 19.1% were in the movement and storage of goods, 15 or 22.1% were in a hotel or restaurant, 4 or 5.9% were the insurance or financial industry, 12 or 17.6% were in education.

[9] In 2013 the average church, local and cantonal tax rate on a married resident, with two children, of Wyssachen making 150,000 CHF was 12.3%, while an unmarried resident's rate was 18.9%.

[20] In 2011 a total of 1.9% of the population received direct financial assistance from the government.

In the federal election, a total of 486 votes were cast, and the voter turnout was 49.7%.

[22] From the 2000 census[update], 987 or 82.4% belonged to the Swiss Reformed Church, while 43 or 3.6% were Roman Catholic.