James Johnston (born 1966, Guildford, Surrey, England) is an English alternative rock musician.
Johnston founded the London-based alternative rock band Gallon Drunk with Michael Delanian, Nick Coombe and Max Decharne in 1990. The group have been active, both recording and touring, to the present, releasing eight studio albums, compilations, and one live album.
Johnston and Terry Edwards provided the musical accompaniment for Derek Raymond's spoken word album Dora Suarez in 1994.
Johnston was a member of Nick Cave and the Bad Seeds from 2003 to 2008, having originally toured as a guest guitarist with the band in 1994 on the Lollapalooza tour. He has also recorded and toured with a wide variety of other musicians, including Barry Adamson and Faust. Johnston has acted in a number of independent movies including Clean (2004) by Olivier Assayas, The Fall of the Louse of Usher by Ken Russell, as well as contributing scores to numerous film and television projects.