(died 1109) was archbishop of Mainz
from 1089 to 1109.
In 1096 he opposed violence against the Jews arising from the First Crusade, trying to turn Emicho away from Mainz. After a two-day stand-off, Emicho broke into the city, and caused a massacre.
He was then accused by Emperor Henry IV, whom he opposed in the Investiture Conflict, of appropriating property of murdered Jews. Ruthard left his diocese until 1105.
He founded Disibodenberg Abbey in 1108 at the place where Disibod had built a cell at the confluence of the rivers Nahe and Glan..