Ferdinand Knab was a German painter.

Knab was initially a student of Heideloff in Nuremberg, where he practically worked in construction for two years, and went to Munich in 1859 to devote himself to architectural painting. He attended Arthur von Ramberg's and Piloty's schools and went to Italy in 1868.

Knab created eight pictures for the royal pavilion at Munich train station. In 1870 he was commissioned with the stage design for Mozart's “Magic Flute” at the court opera.