Lebensreform ("life-reform") is the German generic term for various social reform movements, that started since the mid-19th century and originated especially in the German Empire and later in Switzerland. Common features were the criticism of industrialisation, materialism and urbanization combined with striving for the state of nature. The painter and social reformer Karl Wilhelm Diefenbach is considered to be an important pioneer of the Lebensreform ideas. The various movements did not have an overarching organization, but there were numerous associations. Whether the reform movements of the Lebensreform should be classified as modern or as anti-modern and reactionary is controversial. Both theses are represented.

Karl Wilhelm Diefenbach was a German painter and social reformer.