Witterswil (Swiss German: Witterschwyl) is a municipality in the district of Dorneck in the canton of Solothurn in Switzerland.

Witterswil has an area, as of 2009[update], of 2.67 square kilometers (1.03 sq mi).

Of the rest of the land, 0.37 km2 (0.14 sq mi) or 13.9% is settled (buildings or roads).

[7] Most of the population (as of 2000[update]) speaks German (1,182 or 91.6%), with French being second most common (30 or 2.3%) and Italian being third (27 or 2.1%).

[8] As of 2008[update], the gender distribution of the population was 50.1% male and 49.9% female.

[6] The age distribution, as of 2000[update], in Witterswil is; 96 children or 7.4% of the population are between 0 and 6 years old and 239 teenagers or 18.5% are between 7 and 19.

The greatest number of single family homes (95) were built between 1961 and 1970.

[7] The historical population is given in the following chart:[12] In the 2007 federal election the most popular party was the SVP which received 25.89% of the vote.

In the federal election, a total of 485 votes were cast, and the voter turnout was 50.7%.

[7] There were 659 residents of the municipality who were employed in some capacity, of which females made up 40.8% of the workforce.

The number of jobs in the secondary sector was 122 of which 108 or (88.5%) were in manufacturing and 15 (12.3%) were in construction.

In the tertiary sector; 19 or 12.2% were in wholesale or retail sales or the repair of motor vehicles, 1 was in the movement and storage of goods, 5 or 3.2% were in a hotel or restaurant, 4 or 2.6% were in the information industry, 5 or 3.2% were the insurance or financial industry, 79 or 50.6% were technical professionals or scientists, 26 or 16.7% were in education and 3 or 1.9% were in health care.

[7] From the 2000 census[update], 516 or 40.0% were Roman Catholic, while 404 or 31.3% belonged to the Swiss Reformed Church.

It was open a total of 250 days with average of 42 hours per week during that year.