Moya Costello grew up in Sydney, and graduated with BA from the University of Sydney, 1973 and Dip Ed Sydney Teacher's College, 1973. She gained a Grad. Dip. Media Studies at the Victoria State College, 1983, completed an MA (Literary Studies) at Deakin University, 1996, and received her PhD from the University of Adelaide. Costello has lived in South Australia since 1984, and has worked as a writer, editor and teacher. She has been Producer/Editor of Author's Proof (1986-90) and has contributed to the Science Show (1989) and Arts Today (1994), as well as writing 14 episodes of the children's television program Here's Humphrey (1988-1990).
Costello has taught writing in TAFE, community-based groups and Continuing Education and University seminars since 1982, and has edited several anthologies arising from those classes. She has been a guest reader at events and venues around Australia since 1980, and was Writer-in-Residence at Monash University, 1996. She won a Literature Board grant in 1984 and a South Australian Department of the Arts grant in 1987 and 1994, as well as a Varuna Fellowship in 1994 and the Barbara Hanrahan Fellowship in 1996. She was on the judging panel (non-fiction) for the 1996 Adelaide Festival Awards for Literature, and on the Writers' Week Committee for the 1998 Adelaide Festival, and was a guest at the Sydney Writers' Festival 2000.