Karl Erb (13 July 1877 – 13 July 1958) was a German tenor vocalist who made his career first in opera and then in oratorio and lieder recital. He excelled in all these genres, and before 1920 gave classic performances of key roles in modern works, and created lead roles in those of Hans Pfitzner. He was the first husband of Maria Ivogün and was considered by many the ideal Evangelist in the St Matthew Passion of Johann Sebastian Bach