James Robert Johnston (born 25 April 1980) is a Scottish bassist, vocalist, and songwriter for Scottish group Biffy Clyro.
Johnston was born and raised in Carmunnock, Glasgow before the family moved to Kilmarnock, with his twin brother Ben (who became the drummer for Biffy Clyro), and his younger brother, Adam Johnston (who was Biffy Clyro's drum tech).
Having previously played bass with schoolfriend Simon Neil and brother Ben Johnston in a band called Skrewfish in 1995, the trio moved to Glasgow, and were discovered by manager Dee Bahl, and then signed to Beggars Banquet, in 2001.
Johnston plays bass guitar when the conceptual rock duo Marmaduke Duke plays live.
Johnston is fond of cycling, and cycles around the hills of Ayrshire.
On 15 December 2025, Johnston announced that he would be absent from Biffy Clyro's upcoming tours to seek treatment for addiction issues caused by mental health problems.
The following is a list of musical equipment used by James Johnston.
Johnston's basses are usually tuned to Biffy Clyro's preferred tuning of (DADG), but sometimes (BADG) for "Pause it and Turn It Up" and (CGCF) for "Living is a Problem Because Everything Dies", as well as "That Golden Rule", "The Captain" and "Got Wrong".
His tech is Dave White