Ruth Vermehren (1894–1983) was a Danish Lutheran priest, one of the first three women to become priests of the Church of Denmark.
An active member of the Danish Women's Society, she was frequently invited to preach at the organization's events.
As a result of legislation introduced by the Church Minister Carl Hermansen in 1947, the following year, together with Johanne Andersen and Edith Brenneche Petersen, she was ordained by Bishop Hans Øllgaard in Odense Cathedral.
Denmark thus became the first country in the world to have women priests.
Vermehren then served as a priest in Copenhagen's Women's Prison until she retired in 1964.