September 1949 in Bern) was a Swiss Reformed pastor, Christian socialist, and hymn writer.
The writer Otto von Greyerz [de] was his brother.
After studying theology in Basel, Jena, Bern, Berlin and Paris, he became pastor in Bürglen (Aegerten near Biel) in 1895, in Winterthur in 1902, in Kandergrund in 1912 and in 1918 at the Johanneskirche in Bern [de], where he stayed until 1935.
After the First World War he advocated for Christian pacifism and the introduction of alternative civilian service.
Karl von Gruyerz created a pacifist version of the hymn "Holy God, We Praise Thy Name", which is number 518 in the hymn book of the Evangelical Reformed Churches in German-speaking Switzerland and number 729 in the prayer and hymn book of the Christian Catholic Church in Switzerland.