Gavin Harrison (born 28 May 1963) is an English musician from Hertfordshire, best known for playing drums with the progressive rock bands Porcupine Tree and King Crimson.

Gavin Harrison was Porcupine Tree’s first choice as a replacement drummer. Interestingly enough, that choice stemmed from the friendship Gavin Harrison had struck with Richard Barbieri, Japan’s and Porcupine Tree’s synthesizer player and keyboardist. After meeting at the recording sessions for Alice’s Mezzogiorno Sulle Alpi, Gavin Harrison and Richard Barbieri kept working on various projects and sessions together, including Gavin Harrison’s solo effort.

Since joining Porcupine Tree, Gavin Harrison has recorded drums for the studio albums In Absentia (2002), Deadwing (2005), Fear Of A Blank Planet (2007), and The Incident (2009).

In 2007, Gavin Harrison joined King Crimson and began a long term collaboration with singer and multi-instrumentalist 05Ric.

Gavin Harrison has also taken a stab at the world of drum education. He has written three books: Rhythmic Illusions (1998), Rhythmic Perspectives (2000), and Rhythmic Designs (2010) with Terry Branam, and produced two DVDs: Rhythmic Visions (2002) and Rhythmic Horizons (2007).

Gavin Harrison is also a member of The Pineapple Thief and is involved in many other ventures, including a solo album and game soundtracks.