Viktor von Lang (2 March 1838 – 3 July 1921) was an Austrian chemist.

Lang earned his doctorate from the University of Giessen in 1859 with a thesis titled "Physikalische Verhältnisse kristallisierter Körper".

[1] His book on introductory theoretical physics, Einleitung in die theoretische physik, was published in eight editions from 1867 to 1891.

With crystallographer Wilhelm Josef Grailich, he was co-author of Untersuchungen über die Physikalischen Verhältnisse Krystallisirter Körper ("Investigations into the physical conditions of crystallized bodies").

[2] The mineral langite was named in his honor by Nevil Story Maskelyne.