Gavin Harrison is a British drummer and percussionist. He is best known for playing with the British progressive rock band Porcupine Tree which he joined in 2002. As of 2011, he also plays with the band King Crimson.

Harrison has authored two instructional drum books entitled Rhythmic Illusions and Rhythmic Perspectives. He also wrote and produced his own instructional DVDs, Rhythmic Visions and Rhythmic Horizons, at his home studio. 2010 saw the release of Rhythmic Designs, a book of transcriptions by Terry Branam, and a 3 hour DVD of Gavin's explanations and demonstrations. It won 'Best In Show' at the summer NAMM show in the USA.

In 2007 Gavin began a long term collaboration with singer/extended range bass player 05Ric which led to the release of two CDs Drop and then in 2009 Circles.

In 2008, Gavin joined King Crimson as part of a dual-drummer lineup with Pat Mastelotto. Gavin played a number of shows in the United States in August with the band.

He won the Modern Drummer magazine readers' poll for "best progressive drummer of the year" consecutively from 2007-2010. He is the featured cover story on Modern Drummer January 2009. Rolling Stone Magazine polls rate him as the third best drummer in the past 25 years. His influences come from his father's jazz collection and from drummers such as Steve Gadd and Jeff Porcaro. Kit Studies with Joe Hodson, Paul Brodie and Dave Cutler (Berklee '78 graduate - teacher relating to the evolving Gary Chaffee school of rhythmic concepts).