Marshall Estus Sehorn (June 25, 1934 – December 5, 2006) was an American A&R man, songwriter, music publisher and entrepreneur who played an important role in the development of R&B and popular music in New Orleans between the 1950s and 1970s, particularly as the business partner of record producer Allen Toussaint.
He was born in Concord, North Carolina, and played guitar in local bands while attending North Carolina State University. After graduating, he moved to New York City in 1958, and joined the A&R staff at Bobby Robinson's Fury and Fire record labels as their Southern promotions executive. He soon discovered singer Wilbert Harrison, whose recording of the Leiber and Stoller song "Kansas City" topped the US pop and R&B charts in 1959. The following year he secured another chart-topper for the Fire label, when he signed flamboyant New Orleans singer Bobby Marchan, who had a hit with "There's Something on Your Mind". He also discovered Lee Dorsey, pairing him with young songwriter and pianist Allen Toussaint, and helped secure hits for Gladys Knight and the Pips and Buster Brown. He ran sessions for the Fire and Fury labels in New Orleans, until the labels collapsed in 1963. He was credited as co-writer on many recordings including "One Way Out", which is usually credited to Sehorn and Elmore James.