Matthieu Hartley (born 4 February 1960) is an English musician, best known as the keyboardist for The Cure from 1979-1980.

Hartley was born in Smallfield, England, near Crawley, and was a childhood friend of future bandmate Simon Gallup. Hartley and Gallup were both members of the punk bands Lockjaw and the Magazine Spies in the late 1970s.^[1] These bands often played alongside early versions of the Cure.^[2]

Near the end of 1979, The Cure needed a new bassist following the departure of founding member Michael Dempsey, and recruited Gallup for the position.^[3] Gallup suggested adding Hartley as the band's first full-time keyboardist to broaden their sound.^[4]

Hartley was a full member of the Cure for their 1980 album Seventeen Seconds and the ensuing tour. During this period he contributed to the brief Cure side project Cult Hero.^[5] He left the band later that year due to disagreements with group leader Robert Smith,^[1] and dissatisfaction with the minimalist keyboard requirements in Smith's songs.^[3][6]

After leaving the Cure, Hartley remained friends with Gallup and was an early member of the band that became Fools Dance. He released a solo album under the name Matthieu in 1987, and in 2005 joined the psychedelic rock band The Speak.^[1]