Ernst Karl Abbe (January 23, 1840 – January 14, 1905) was a German physicist and professor at the University of Jena. He was born in Eisenach, Saxe-Weimar-Eisenach, and died in Jena. Abbe is best known for his work in optics.

The Chambers Biographical Dictionary says of him that "he was inventor of the arrangement known as Abbe's homogenous immersion."[1]