Leonhard Ragaz (28 July 1868 – 6 December 1945) was a Swiss Reformed theologian and, with Hermann Kutter, one of the founders of religious socialism in Switzerland. He was influenced by Christoph Blumhardt. He was married to the feminist and peace activist Clara Ragaz-Nadig.

Born to a farmer family in Tamins, Grisons, on 28 July 1868, Ragaz studied theology in Basel, Jena, and Berlin. In 1890, he was elected as minister in Flerden, Heinzenberg. In 1893, he moved to Chur, working as a teacher of language and religion, and from 1895 to 1902 as municipal minister. In 1902, Ragaz was elected as minister at the Basel Minster.

Leonhard Ragaz grew up as the son of a small farming family in the municipality of Tamins. After studying theology in Basel, Jena and Berlin, he became a pastor in Flerden, Heinzenberg in 1890. In Swiss Zofingen Association. 1892 he took up a position as a language and religion teacher in Chur and was elected parish priest in 1895, and in 1902 he moved to Basel Minster as the second pastor. Here his first book was created, the ethical draft: You are said to do!

In Basel, including reading the works of Hermann Kutter, Ragaz came into contact with the labour movement. As construction workers went on strike in 1903, Ragaz delivered a sermon in his famous masonry watch on the cathedral cockpit "if institutional Christendom were to be cold and incomprehending towards the becoming of a new world, which after all emerged from the heart of the gospel, then the salt of the earth would have become putrid". which came to be known as the "bricklayers' strike sermon" (Maurerstreikpredigt). Since 1906, Kutter and he have collected like-minded people at annual religious-social conferences. In addition, Ragaz gave the magazine with Benedikt Hartmann (1873-1955) and Rudolf Lichtenhand (1875-1947)

In 1908, Ragaz was appointed to the Theological Faculty of the University of Zurich as Professor of Systematic and Practical Theology. He joined the Social Democratic Party of Switzerland in 1913. He was Shocked during the First World War by European Nationalism, he campaigned for the international cooperation of social democracy and helped to prepare the Zimmerwald Conference in 1915. During the Swiss general strike [als; de; fr; he] of 1918, he took sides with the workers, when the soldiers guarded the university with their steel helmets and planted bayonets, he protested: "this site had to be protected only because it had given the people stones instead of bread"

In 1921 at the age of 53, Ragaz resigned from his chair because it had become impossible for him to train pastors for the bourgeois Swiss Reformed Church. He and his family moved to the proletarian Aussersihl district of Zürich. He remained involved with the labour movement, editing his journal Neue Wege he was recognised and been added to the International Reconciliation Society to maintain peace, until his death in Zürich on 6 December 1945.

For Ragaz, the Early Church was based on a spirit of cooperation and collectivity. As a consequence, the socialist ideal of self-administered cooperatives owned by the workers themselves was a postulate directly derived from the gospel and the promise of justice in God's kingdom.

Also as a consequence of his Christian belief in justice and peace, Ragaz staunchly opposed the First World War, from a stance of active pacifism: he called for all religious socialists to unite in protesting the war. He taught that if capitalism resorted to force and violence, that was a true reflection of its nature, but that if socialism did the same, it was a treason to its ideals.