Ergisch is a municipality in the district of Leuk in the canton of Valais in Switzerland. Ergisch is first mentioned in 1203 as Mons de Argessa. Ergisch has an area, , of . Of this area, 20.9% is used for agricultural purposes, while 38.0% is forested. Of the rest of the land, 0.9% is settled (buildings or roads) and 40.1% is unproductive land. The municipality is located in the Leuk district, at an elevation of on the slope left side of the Rhone valley at the entrance to the Turtmann valley. The blazon of the municipal coat of arms is Per fess Azure three Mullets of Six Argent one and two and Gules a Fleur-de-lis and a Double Cross of the second. Ergisch has a population () of . , 5.2% of the population are resident foreign nationals. Over the last 10 years (1999–2009 ) the population has changed at a rate of 17.5%. It has changed at a rate of 11.3% due to migration and at a rate of -6.9% due to births and deaths. All of the population () speaks German. the gender distribution of the population was 50.0% male and 50.0% female. The population was made up of 89 Swiss men (47.3% of the population) and 5 (2.7%) non-Swiss men. There were 89 Swiss women (47.3%) and 5 (2.7%) non-Swiss women. Of the population in the municipality 118 or about 67.0% were born in Ergisch and lived there in 2000. There were 39 or 22.2% who were born in the same canton, while 15 or 8.5% were born somewhere else in Switzerland, and 4 or 2.3% were born outside of Switzerland. The age distribution of the population () is children and teenagers (0–19 years old) make up 25.6% of the population, while adults (20–64 years old) make up 54.5% and seniors (over 64 years old) make up 19.9%. there were 76 people who were single and never married in the municipality. There were 82 married individuals, 15 widows or widowers and 3 individuals who are divorced. there were 68 private households in the municipality, and an average of 2.6 persons per household. There were 19 households that consist of only one person and 7 households with five or more people.