Iain Matthews is an English musician and songwriter. He was a singer with Fairport Convention before forming his own band, Matthews Southern Comfort, which had a UK number one in 1970 with a cover version of Joni Mitchell's song "Woodstock".

Born in Scunthorpe, Lincolnshire, England, Matthews was known in the 1960s as Ian McDonald, then as Ian Matthews. In 1989, he reverted to the original spelling of his first name.

Influenced by both rock & roll and folk music, he has performed mainly as a solo act, although he was a member of Fairport Convention during the early period when they were heavily influenced by American folk music. He later had a solo career and led the bands Plainsong, Hi-Fi, No Grey Faith, More Than A Song, and Matthews Southern Comfort.