IA, Ia, or ia may refer to:
Sir Ian Murray McKellen (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 James Thorpe, (born 13 October 1982) is a retired Australian swimmer who specialised in freestyle, but also competed in backstroke and the individual medley.
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 Richard Kyle Paisley, Baron Bannside, (6 April 1926 – 12 September 2014), was a loyalist politician and Protestant religious leader from Northern Ireland.
Ian Kevin Curtis (15 July 1956 – 18 May 1980) was an English singer-songwriter and musician. He is best known as the lead singer and lyricist of the post-punk rock band Joy Division.
Ian Edward Wright, MBE (born 3 November 1963) is an English former professional footballer turned television and radio personality.
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.
Ian Russell McEwan (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 The Daily Telegraph ranked him number 19 in their list of the "100 most powerful people in British culture".