Franz Xaver Simm was an Austrian painter and illustrator.

The son of a family of painters studied from 1869 to 1876 at the Vienna Academy of Fine Arts under Eduard von Engerth and Anselm Feuerbach. He received in 1876 a two-year traveling scholarship to Rome and remained until 1881 in Italy. There he married Marie Mayer, also a painter. They went then to Tbilisi to perform there in the Caucasian Museum murals. Later he lived in Munich, where he accepted a professorship.

Simm worked mainly as an illustrator. Later he created increasingly small genre paintings in the Empire style.