Ian Richard McDonald (25 June 1946 – 9 February 2022) was an English musician, composer and multi-instrumentalist, best known as a founding member of the progressive rock band King Crimson in 1968, as well as the hard rock band Foreigner in 1976.

McDonald began his music career as an army musician, where he learned the clarinet and taught himself music theory. He also taught himself to play flute, saxophone, guitar and piano. He co-founded King Crimson and appeared on their 1969 debut album In the Court of the Crimson King, playing Mellotron, keyboards and woodwinds. In the mid-1970s, he moved to New York City where he co-founded Foreigner, appearing on the group's first three albums. He later collaborated with Steve Hackett and played in the King Crimson spin-off group 21st Century Schizoid Band. He was also a session musician, predominantly as a saxophonist. In 2024, McDonald was posthumously selected for induction into the Rock and Roll Hall of Fame, as a member of Foreigner.