Bobby Johnston (born 1967 in Olean, New York) is a Los Angeles based film composer, multi-instrumentalist and author. He has composed original music scores for several films, including King of the Ants, Wristcutters: A Love Story, Edmond, Stuck, Mother's Day, Marfa Girl, Bleed Out and City of Gold. He often worked with director Stuart Gordon.

Johnston became known for an unusual approach to film composition, using only acoustic instruments and usually performing every instrument himself. Over his career, he has also brought in many instrumental soloists to accent his sound. Most notable are his scores to Edmond, which featured trumpet player Asdru Sierra from Ozomatli and Crazy Eyes, featuring Big Sir vocalist Lisa Papineau. He also worked with percussionist Greg Ellis on the scores to A New York Heartbeat, Mother's Day and The Barrens.

Johnston was a performer at the Sundance Music Café as part of the 2006 Sundance Film Festival, where Wristcutters: A Love Story had its world premiere.

Johnston's composition I'm Leaving You was featured on the soundtrack to the 2013 film The Lone Ranger.

His music has often been heard on the popular radio program This American Life and has been included on two of the show's greatest hits CDs.

Johnston's first book, "The Saint I Ain't: Stories from Sycamore Street" was published by Fomite Press on February 9, 2021. It is a collection of fictional short stories presented in a hybrid style of poetry and personal narrative.