Alan Lindsay Mackay FRS (born 6 September 1926) is a British crystallographer, born in Wolverhampton. He spent his scientific career at Birkbeck College, founded by George Birkbeck, one of the Colleges of the University of London, where he was immersed in a liberal scientific atmosphere under the leadership of John Desmond Bernal. For his contributions to quasicrystals in 2010 Mackay was awarded the Buckley Prize, of the American Physical Society, with Dov Levine and Paul Steinhardt. The Nobel Prize in Chemistry was awarded in 2011 to Dan Shechtman for the discovery of quasicrystals.