Derek John "Blue" Weaver (born 11 March 1947) is a Welsh rock keyboardist, session musician, songwriter and record producer.

[1] After playing with several local bands, he moved to London and joined "The Heatwave", who backed Tawny Reed.

Weaver's career as a musician began as a co-founding member of 1960s Welsh rock band Amen Corner and its successor Fair Weather.

[citation needed] In 1975, former Amen Corner bandmate Dennis Bryon, who had begun playing drums in The Bee Gees backing band the year before, suggested Weaver as a replacement keyboardist for the band following the departure of Geoff Westley.

[1] As a songwriter and composer, Weaver was credited as a co-composer on Andy Gibb's hit song, "(Our Love) Don't Throw It All Away", as well as songs for Jimmy Ruffin's 1980 album Sunrise with Robin Gibb as lyricist, including the top 10 hit single, "Hold On To My Love”.