IA, Ia, or ia may refer to:
Sir Ian Murray McKellen, CH, CBE (born 25 May 1939) is an English actor. He is the recipient of six Laurence Olivier Awards, a Tony Award, a Golden Globe Award, a Screen Actors Guild Award, a BIF Award, two Saturn Awards, four Drama Desk Awards, and two Critics' Choice Awards.
Ian Lancaster Fleming (28 May 1908 – 12 August 1964) was an English author, journalist and naval intelligence officer who is best known for his James Bond series of spy novels.
Ian Edward Wright, MBE (born 3 November 1963) is an English former professional footballer turned television and radio personality.
George Iain Duncan Smith (born 9 April 1954), often referred to by his initials IDS, is a British Conservative Party politician.
Ian Richard Kyle Paisley, Baron Bannside, PC (6 April 1926 – 12 September 2014) was a loyalist politician and Protestant religious leader from Northern Ireland.
Ian James Poulter (born 10 January 1976) is an English professional golfer who is a member of the world's top two professional golf tours, the U.S.-based PGA Tour and the European Tour.
Iain Banks (16 February 1954 – 9 June 2013) was a Scottish author. He wrote mainstream fiction under the name Iain Banks and science fiction as Iain M.
Ian Russell McEwan CBE FRSA FRSL (born 21 June 1948) is an English novelist and screenwriter. In 2008, The Times featured him on their list of "The 50 greatest British writers since 1945", and also in 2008 The Daily Telegraph ranked him number 19 in their list of the "100 most powerful people in British culture".