Gregory Stuart Lake (10 November 1947 – 7 December 2016) was an English musician, singer, and songwriter. He gained prominence as a founding member of the progressive rock bands King Crimson and Emerson, Lake & Palmer (ELP).

Born and brought up in Dorset, Lake began to play the guitar at the age of 12 and wrote his first song, "Lucky Man", at the same age. He became a full-time musician at 17, playing in several rock bands until his friend and fellow Dorset guitarist Robert Fripp invited him to join King Crimson as lead singer and bassist. They found commercial success with their influential debut album, In the Court of the Crimson King (1969).

Lake left the band in 1970 and achieved significant success in the 1970s and beyond as the singer, guitarist, bassist, and producer of ELP. As a member of ELP, Lake wrote and recorded several popular songs including "Lucky Man" and "From the Beginning". Both songs entered the UK and US singles charts. Lake launched a solo career, beginning with his 1975 single "I Believe in Father Christmas" which reached number two in the UK. He went on to release three solo albums with his Greg Lake Band and guitarist Gary Moore, recorded 1981 through 1983 (two studio albums, one live album). He was also briefly but notably a member of pop rock band Asia in 1983, replacing vocalist/bassist John Wetton (another former member of King Crimson) for three concerts in Tokyo, Japan. As well as collaborating and performing with other artists and with various groups in the 1980s, he had occasional ELP reunions in the 1990s and in 2010, and toured regularly as a solo artist into the 21st century.

Lake also sponsored other artists, producing their recordings and helping them to get recording contracts. He also was a fundraiser for the National Center for Missing & Exploited Children. He died on 7 December 2016 in London, of pancreatic cancer, at the age of 69.