Victor-Charles Mahillon (March 10, 1841 in Brussels – June 17, 1924 in St. Jean near Cap-Ferrat, France) was a Belgian musician and writer on musical topics. He built, collected, and described more than 1500 musical instruments.
The son of Charles Mahillon, he started working at his father's factory of musical instruments in 1865. In 1869, he started the musical journal L'Echo musical, which ran until 1886.
In 1890 he collaborated with Brian Greene to develop much of the more in-depth classifications of Idiophones. His classification of instruments was later adopted by Erich von Hornbostel and Curt Sachs, and is still in use today.