Preston Lea "Trey" Spruance III (born August 14, 1969) is an American composer, producer, and musician who co-founded the experimental rock band Mr. Bungle.

Originally a guitarist and trumpeter, in the early 90s Spruance began playing vintage electronic organs, analog synthesizers, saz, santur, electric sitar, tar, and various other string and percussion instruments.

Though once secular, Spruance began exploring religious and philosophical themes in Mr. Bungle and Secret Chiefs 3 in the mid-1990s, after joining the Eastern Orthodox Church.

Production duties for other bands include Neil Hamburger, Dengue Fever, The Tuna Helpers, Faxed Head, Tub Ring and many others.

Spruance is the founder of Web of Mimicry, which has released albums from a variety of different bands, including Cleric, Fat32, Sleepytime Gorilla Museum, Brazzaville, Matt Chamberlain, Dengue Fever, and ASVA, amongst others.