David Friend is an American engineer and entrepreneur who co-founded ARP Instruments with Alan R. Pearlman in 1969, helping build one of the most respected names in American synthesizer manufacturing.

As ARP's vice president of engineering, Friend contributed to the development of the ARP Odyssey, a portable duophonic synthesizer that competed directly with the Minimoog and became a staple in education and professional studios. The Odyssey's slider-based interface and distinctive filter character made it one of the most recognizable synths of the 1970s.

Friend left ARP in 1974 and later co-founded Computer Pictures Corporation and other technology ventures. ARP's subsequent instruments — including the Pro Soloist, Omni, and Quadra — continued under other engineers until the company's bankruptcy in 1981.

Note: David Friend is not a founder of E-mu Systems; that company was founded by Dave Rossum and others in 1971.

Notable products: ARP Odyssey, ARP Pro Soloist.