Karl Ferdinand Sohn was a German painter of the Düsseldorf school of painting.

He was born in Berlin and started his studies at the age of eighteen under Wilhelm von Schadow, whom he followed to Düsseldorf. He focused on mythical and poetic subjects of a highly romantic character, and painted in the idealistic manner of the Düsseldorf school.

He visited Italy (1830–1831) and adopted ideas from the works of the Venetians; Titian, Paolo Veronese, and Palma il Vecchio. In 1832, he was named a Professor at the Düsseldorf Academy, where he exercised an important influence.

On 18 January 1834, he married Emilie Auguste von Mülmann in Düsseldorf. They had five children. His two sons Paul Eduard Richard Sohn (1834–1912) and Karl Friedrich Rudolf Sohn (1845–1908) also grew up to be painters. The latter married Else Sohn-Rethel (1853–1933), daughter of the painter Alfred Rethel. Clara, his eldest daughter, was married to the German composer and conductor Albert Dietrich. His daughter Marie married the painter Karl Hoff (1838–1890). His youngest daughter, Emilie, married his nephew, the painter Wilhelm Sohn (1830–1899), thereby making him his nephew and son-in-law.

Later, He painted biblical subjects, and then devoted himself to genre scenes, well characterized and of great coloristic charm. Among these are: the Consultation at the Lawyer's (1866, Leipzig Museum) and the Warrior of the Seventeenth Century (1869, Dresden Gallery).

At the age of nearly sixty-two Karl Ferdinand Sohn died on 25 November 1867 during a visit to his friend Ferdinand Hiller in Cologne.