Music critics have acknowledged Fish for his voice, which has been described as both "distinct" and a "conflation of Roger Daltrey and Peter Gabriel", while his lyrics have been praised as "poetic prose". In 2004, Classic Rock magazine ranked Fish #49 on the list of "The 100 Greatest Frontmen", describing him with "His theatrical delivery was a major factor in Marillion's spectacular rise, and he masterminded some uniquely ornate lyrical concepts." Fish was voted number 37 in the greatest voices in rock by Planet Rock listeners in 2009.
Derek William Dick was born on 25 April 1958 in Edinburgh, Scotland, and grew up in Dalkeith. The son of Robert and Isabella, Fish was educated at King's Park primary school and then Dalkeith High School. He was inspired by the music of many of the rock artists of the late 1960s and early 1970s, including Genesis, Pink Floyd, the Moody Blues, the Kinks, T. Rex, David Bowie, Argent and the Alex Harvey Band (Fish would later pay tribute to these early influences on his covers album Songs from the Mirror). Fish has also cited Canadian singer-songwriter Joni Mitchell as "one of the biggest influences on me because of her approach to lyrics". The first band he saw live was Yes at Usher Hall, Edinburgh, in 1974. As well as his love for music, he was also a voracious reader, and his literary inspirations included Jack Kerouac, Truman Capote, Robert Burns and Dylan Thomas (all of whom would later be depicted on the sleeve of Marillion's Clutching at Straws).
Fish worked as a petrol pump attendant, gardener and from 1977 until 1980 worked in forestry. During this period he adopted the nickname of Fish, which originated from the amount of time he spent in the bath. Fish has been quoted: "With a real name of Derek William Dick, it became very necessary to find a nickname as quickly as possible."
Fish joined Marillion in 1981. The band gained popularity over the next couple of years, leading to the release of their top ten debut album Script for a Jester's Tear in 1983. They achieved further chart success in the UK, attaining top ten hit singles in 1985 with "Kayleigh" and "Lavender", and again in 1987 with "Incommunicado". In 1988, Fish left Marillion to pursue a solo career.
Many of Fish's later works contain lengthy spoken word lyrics, shorter examples of which can be heard on earlier Marillion albums. Fish has collaborated with Genesis founder Tony Banks on his Still and Soundtracks albums, singing on the tracks "Shortcut to Somewhere", "Angel Face" and "Another Murder of a Day", co-writing the latter.