LFO was a British electronic music act formed in 1988 consisting of Mark Bell and Gez Varley. They released their acclaimed debut LP Frequencies in 1991 on Sheffield label Warp. After Varley left the group in 1996, Bell continued solo to release Advance (1996) and Sheath (2003). Bell died in October 2014, effectively ending the project.

Mark Bell was a British DJ, record producer, and member of the pioneering techno group LFO. He recorded on Warp Records, and also collaborated with artists such as Björk and Depeche Mode.