Lostorf is a municipality in the district of Gösgen in the canton of Solothurn in Switzerland.

[3] Lostorf has an area, as of 2009[update], of 13.26 square kilometers (5.12 sq mi).

while parks, green belts and sports fields made up 1.4%.

[4] The municipality is located in the Gösgen district, near the base of Dottenberg and Reitifluh Mountains.

The blazon of the municipal coat of arms is Or three Roses Gules barbed and seeded proper, slipped and leaved Vert issuant from a Mount of 3 Coupeaux of the last.

[8] Most of the population (as of 2000[update]) speaks German (3,289 or 94.6%), with Italian being second most common (42 or 1.2%) and Serbo-Croatian being third (22 or 0.6%).

[9] As of 2008[update], the gender distribution of the population was 49.8% male and 50.2% female.

[7] The age distribution, as of 2000[update], in Lostorf is; 298 children or 8.6% of the population are between 0 and 6 years old and 596 teenagers or 17.1% are between 7 and 19.

[8] The historical population is given in the following chart:[3][13] In the 2007 federal election the most popular party was the SVP which received 28.96% of the vote.

In the federal election, a total of 1,533 votes were cast, and the voter turnout was 57.6%.

[8] There were 1,849 residents of the municipality who were employed in some capacity, of which females made up 42.1% of the workforce.

In 2008[update] the total number of full-time equivalent jobs was 603.

In the tertiary sector; 113 or 28.8% were in wholesale or retail sales or the repair of motor vehicles, 36 or 9.2% were in the movement and storage of goods, 13 or 3.3% were in a hotel or restaurant, 3 or 0.8% were in the information industry, 10 or 2.6% were the insurance or financial industry, 69 or 17.6% were technical professionals or scientists, 43 or 11.0% were in education and 58 or 14.8% were in health care.

[8] From the 2000 census[update], 1,577 or 45.4% were Roman Catholic, while 1,081 or 31.1% belonged to the Swiss Reformed Church.

The education system in the Canton of Solothurn allows young children to attend two years of non-obligatory Kindergarten.

All the lower secondary students from Lostorf attend their school in a neighboring municipality.