Gary Mervin Thain (May 15, 1948 – December 8, 1975) was a New Zealand bassist, best known for his work with British rock band Uriah Heep.

With drummer Peter Dawkins, he traveled from New Zealand to London, and once jammed with Jimi Hendrix before the trio split in 1969.

During his last U.S. tour with Heep, Thain was seriously injured when he suffered an electric shock at the Moody Coliseum in Dallas, Texas on 15 September 1974.

[3] Due to his drug addiction he was not able to perform properly, and was fired by the band in early 1975 and replaced by former King Crimson bassist/vocalist, John Wetton.

He died of respiratory failure due to a heroin overdose, on 8 December 1975, aged 27,[4] at his flat in Norwood Green in London.