William Scott Gorham is an American guitarist and songwriter who is one of the "twin lead guitarists" for the Irish rock band Thin Lizzy. Although not a founding member of Thin Lizzy, he served a continuous membership after passing an audition in 1974, joining the band at a time when the band's future was in doubt after the departures of original guitarist Eric Bell and his brief replacement Gary Moore. Gorham remained with Thin Lizzy until the band's breakup in 1983. He and guitarist Brian Robertson, both hired at the same time, marked the beginning of the band's most critically successful period, and together developed Thin Lizzy's twin lead guitar style while contributing dual backing vocals as well. Gorham is the band member with the longest membership after founders Brian Downey (drummer) and frontman and bass guitarist, Phil Lynott.

Thin Lizzy are an Irish hard rock band formed in Dublin in 1969. Thin Lizzy initially consisted of bass guitarist, lead vocalist and principal songwriter Phil Lynott, drummer Brian Downey, guitarist Eric Bell and organist Eric Wrixon, although Wrixon left after a few months. Bell left at the end of 1973 and was briefly replaced by Gary Moore, who himself was replaced in mid-1974 by twin lead guitarists: Scott Gorham, who remained with the band until their break-up in 1983, and Brian Robertson, who remained with the band until 1978 when Moore re-joined. Moore left a second time and was replaced by Snowy White in 1980, who was himself replaced by John Sykes in 1982. The line-up was augmented by keyboardist Darren Wharton in 1980. The singles "Whiskey in the Jar" (1972), "The Boys Are Back in Town" (1976) and "Waiting for an Alibi" (1979) were international hits, and several Thin Lizzy albums reached the top ten in the UK. The band's music reflects a wide range of influences, including blues, soul music, psychedelic rock and traditional Irish folk music, but is generally classified as hard rock or sometimes heavy metal.