Mario Diaz de Leon is a New York City-based composer, performer, and educator, whose creative work encompasses modern classical music, experimental electronic music, extreme metal, and improvised music.

Born in Minnesota in 1979, he played guitar in local hardcore punk and metal bands before attending the Oberlin Conservatory of Music, where he studied electronic music and composition. He has lived in New York City since 2004 and received his doctorate in music composition from Columbia University in 2013, where he studied with George Lewis and Fabien Levy.

Noted for bold combination of acoustic instruments and electronics, his compositions have been documented on several recordings, often produced in collaboration with the International Contemporary Ensemble (ICE). A debut album, Enter Houses Of, was released in 2009 on John Zorn's Tzadik label. The second album, The Soul Is the Arena, was released in 2015 on Denovali, and was named a notable recording of 2015 by “New Yorker Magazine”.

From 2012 to 2016, his solo electronic project Oneirogen toured internationally and released three full length LPs and two EPs on the Denovali label. He currently leads the metal band Luminous Vault as vocalist and guitarist. Alongside Jeremiah Cymerman and Toby Driver, he is a member of Bloodmist, a trio devoted to electroacoustic improvisation.