 Millar became the president of the Ulster Rugby Union in 1985, and was appointed as one of the representatives of the Irish Rugby Football Union (IRFU) to the IRB Council in 1992.He became president of the IRFU in 1995, and was also chairman of the British and Irish Lions from 1999 to 2002.In 2002 the IRB Chairman Vernon Pugh became seriously ill. Millar was appointed as Vice-Chairman of the Board of the IRB on 16 September 2002, replacing New Zealander Rob Fisher.