| Official Name: | San Juan de la Costa |
| Settlement Type: | Commune |
| Flag Alt: | Flag |
| Shield Alt: | Coat of arms |
| Map Alt: | Location of the San Juan de la Costa commune in Los Lagos Region |
| Pushpin Map Narrow: | yes |
| Pushpin Map: | Chile |
| Pushpin Label Position: | bottom |
| Pushpin Map Alt: | Location in Chile |
| Pushpin Mapsize: | 175 |
| Pushpin Map Caption: | Location in Chile |
| Coordinates: | -40.5167°N -97°W |
| Subdivision Type: | Country |
| Subdivision Name: | Chile |
| Subdivision Type1: | Region |
| Subdivision Name1: | Los Lagos |
| Subdivision Type2: | Province |
| Subdivision Name2: | Osorno |
| Established Title: | Founded |
| Established Date: | October 26, 1979 |
| Government Type: | Municipality |
| Government Footnotes: | [1] |
| Leader Party: | DC |
| Leader Title: | Alcalde |
| Leader Name: | Bernardo Candia Henríquez |
| Unit Pref: | Metric |
| Area Footnotes: | [2] |
| Area Total Km2: | 1517 |
| Population Total: | 8831 |
| Population As Of: | 2002 Census |
| Population Density Km2: | auto |
| Population Blank1 Title: | Urban |
| Population Blank1: | 902 |
| Population Blank2 Title: | Rural |
| Population Blank2: | 7929 |
| Demographics Type1: | Sex |
| Demographics1 Title1: | Men |
| Demographics1 Info1: | 4,814 |
| Demographics1 Title2: | Women |
| Demographics1 Info2: | 4,017 |
| Timezone: | Chile Time (CLT)[3] |
| Utc Offset: | -4 |
| Timezone Dst: | Chile Summer Time (CLST)[4] |
| Utc Offset Dst: | -3 |
| Area Code: | 56 + |
San Juan de la Costa is a commune of Chile, located in the Osorno Province in the Los Lagos Region. The administration (municipalidad) is located at the hamlet of Puaucho, 34 km west of Osorno. San Juan de la Costa is known for a large proportion of its population being indigenous Huilliches. This commune is characterized by a large coastline suitable for ecotourism, especially balnearios Pucatrihue and Maicolpue, the port of Bahía Mansa, and the ethnic tourism of the Huilliche culture.
According to the 2002 census of the National Statistics Institute, San Juan de la Costa spans an area of 1517sqkm and has 8,831 inhabitants (4,814 men and 4,017 women). Of these, 902 (10.2%) lived in urban areas and 7,929 (89.8%) in rural areas. The population fell by 9.7% (947 persons) between the 1992 and 2002 censuses.[2]
As a commune, San Juan de la Costa is a third-level administrative division of Chile administered by a municipal council, headed by an alcalde who is directly elected every four years. The 2008-2012 alcalde is Javier Oyarzo Ruiz (RN).[1]
Within the electoral divisions of Chile, San Juan de la Costa is represented in the Chamber of Deputies by Javier Hernández (UDI) and Sergio Ojeda (PDC) as part of the 55th electoral district, together with Osorno and San Pablo. The commune is represented in the Senate by Camilo Escalona Medina (PS) and Carlos Kuschel Silva (RN) as part of the 17th senatorial constituency (17).