Junior Campbell (born William Campbell Jnr, 31 May 1947) is a Scottish composer, songwriter and musician. He was a founding member, lead guitarist, piano player, and singer with the Scottish band Marmalade and co-wrote and produced some of their biggest successes, including "Reflections of My Life", "I See the Rain" and "Rainbow".
"Reflections of My Life" has produced sales of over two million units. In 1998 Campbell and co-writer Dean Ford (Thomas McAleese) were awarded a Special Citation of Achievement by the BMI for attaining radio broadcast performances in excess of one million in the US alone.
He also wrote and produced his own solo hits, Hallelujah Freedom and Sweet Illusion and "Carolina Days".
Campbell is also known for composing music for film and television drama, and as an arranger and producer for many musicians including Barbara Dickson. He is also known for co-composing the music and co-writing the lyrics for 182 episodes and 31 songs of the children’s TV series Thomas & Friends from 1983–2003, including "The Island Song", "He’s A Really Useful Engine", "The Snow Song" and "Accidents Happen", and also composing the music for Tugs, a thirteen part children’s television series from the same production crew as Thomas.