Paimio Sanatorium is a former tuberculosis sanatorium in Paimio, Southwest Finland, designed by Finnish architect Alvar Aalto. Aalto received the design commission having won the architectural competition for the project held in 1929. The building was completed in 1933, and soon after received critical acclaim both in Finland and abroad. The building served exclusively as a tuberculosis sanatorium until the early 1960s, when it was converted into a general hospital. Today the building is owned by Turku University Hospital but is not functioning as a hospital; rather, the building has functioned as private rehabilitation center for children since 2014. The sanatorium has been nominated to become a UNESCO World Heritage Site.

A sanatorium, also sanitarium or sanitorium, is a historic name for a specialised hospital for the treatment of specific diseases, related ailments and convalescence. Sanatoriums are often in a healthy climate, usually in the countryside. The idea of healing was an important reason for the historical wave of establishments of sanatoriums, especially at the end of the 19th- and early 20th centuries. One sought, for instance, the healing of consumptives especially tuberculosis or alcoholism, but also of more obscure addictions and longings of hysteria, masturbation, fatigue and emotional exhaustion. Facility operators were often charitable associations such as the Order of St. John and the newly founded social welfare insurance companies.