Derek William Dick (better known as Fish; born 25 April 1958, in Dalkeith, Midlothian, Scotland), is a Scottish progressive rock singer, lyricist and occasional actor, best known as the original lead singer of Marillion.

Fish was educated at Dalkeith High School. After working as a petrol pump attendant, gardener and forestry worker, Fish came to the public's attention in 1981 with the British rock group Marillion. The band achieved chart success in the UK, attaining top-ten hits in 1985 with "Kayleigh" and "Lavender", and again in 1987 with "Incommunicado". In 1988, Fish left Marillion in order to pursue his solo career. Many of Fish's later works contain lengthy spoken word lyrics, shorter examples of which can be heard on earlier Marillion albums. Vocally, Fish has sometimes been compared to Peter Gabriel, lead singer of Genesis in the 1970s. Music journalist David Hepworth described his voice as a “conflation of Roger Daltrey and Peter Gabriel”.

According to Fish himself, his nickname originates from the amount of time he spent in the bathtub. Fish has one daughter, Tara.

On 26 August 2007, Fish performed at the 'Hobble on The Cobbles' show at the Market Square in Aylesbury, UK. He was accompanied on stage by four Marillion members (Mark Kelly, Steve Rothery, Ian Mosley and Pete Trewavas) for one song: 'Market Square Heroes'. This was the first time they had performed together in nearly two decades. In a press interview following the event, Fish denied this would lead to a full reunion, claiming that "Hogarth does a great job with the band... We forged different paths over the 19 years."

His most recent studio album, 13th Star, was released on 12 September 2007 as a specially-packaged pre-release version available to order from his website. A UK tour for this album commenced in March 2008, supported by Glyder. In February 2008, Fish was confirmed to be the Friday night headline act at NEARFest X. He also appeared with BBC Radio 2's Bob Harris on GMTV to promote Childline Rocks, a charity concert.

In 2008, Fish presented a Friday evening radio show "Fish on Friday" for digital radio station Planet Rock. When the station was faced with closure, Malcolm Bluemel with the help of Fish, Tony Iommi, Ian Anderson and Gary Moore helped save Planet Rock by buying the station.

On 9 June 2008, Fish embarked on his first full North American tour in eleven years. At each stop, he hosted a pre-show meet-and-greet with his fans. Two days prior, he was interviewed by Vince Font of the progressive rock podcast Prog'opolis, which was aired a week later on The Dividing Line Broadcast Network (DLBN) as "My Lunch With Fish".

In 2008, Fish revealed that he would be taking at least six months off from singing due to an "irregular cell growth" in his throat. This was later determined not to be cancerous.

Fish is a keen supporter of Scottish Premier League side Hibernian F.C.

In 2005, Fish won a Celebrity Music edition of The Weakest Link beating Eggsy of Goldie Lookin Chain in the final round sharing £18,750 with Eggsy's charity and his own.