Millett was an air gunner in England during the Second World War. A trained lawyer, he became the managing editor of Poetry Australia in 1967. After the death of Grace Perry (q.v.), Millett was editor of Poetry Australia from 1988 to 1992 and then helped to establish the Poetry Australia Fund which was instrumental in the establishment in 2002 of the magazine Blue Dog: Australian Poetry. He published and reviewed extensively in Australia, the UK and the USA.