Jack Lancaster is a British composer, record producer and musician.
In the late 1960s, Lancaster co-founded the British rock group Blodwyn Pig with Jethro Tull guitarist Mick Abrahams and in the late 1970s he was a member of the British progressive rock group Aviator with former Jethro Tull drummer Clive Bunker, former Manfred Mann's Earth Band guitarist Mick Rogers, and former Caravan and Quantum Jump bassist John G. Perry that released two albums on the EMI America Records label (Lancaster appeared only on the band's debut). In between these high-profile projects, Lancaster collaborated with keyboardist Robin Lumley in the studio band The Soul Searchers with a line-up that included guitarists John Goodsall and Gary Moore, bassist Percy Jones, and drummer Bill Bruford. This group released one 7" single Scaramouche b/w Head Stand in 1975 for EMI Records.
Lancaster performed on two Jazz Fusion records with Lumley that were released by RSO Records in the mid-1970s. The first was a rock version of Russian composer Sergei Prokofiev's Peter and the Wolf, The Rock Peter and the Wolf (1975), and the second titled Marscape (1976) that both featured the contributions of members of what would become Lumley's future band Brand X (John Goodsall on guitar, Percy Jones on bass, and Phil Collins on drums).