Ernst Sieber (German pronunciation: [ɛʁnst ˈziːbɐ] ⓘ; 24 February 1927 – 19 May 2018) was a Swiss pastor, social activist and politician who served one term as a member of the National Council (Switzerland) for the Evangelical People's Party.

[2] In 1963 he initiated the basis for the relief organisation Sozialwerke Pfarrer Sieber, founded in 1988 for "disadvantaged people, to help to alleviate the hardships around addiction, disease, violence and homelessness".

[3] Sieber called himself a "dreamy child, I preferred to go fishing with my brother than to go to school", but also he said on occasion of an interview in February 2015: "The sense of justice and for the most vulnerable people in society has always been in me".

[5] In Winter 1963 Sieber initiated a shelter for homeless and marginalized people in Zürich-Aussersihl, and began to establish further projects, among others for drug addicts at Platzspitz park and Letten in the 1980s.

[15] To give pastoral, social, medical and material assistance, as well as to ensure partnership and mutually complementary aid, SWS states that it cooperates with individuals, private, civil and ecclesiastical authorities.