A fourth-generation South Australian, Ann Clancy was born and raised in Adelaide, in a lfamily of five children. Both her parents were teachers and she grew up in an environment of books and ideas. When Clancy was nine her family spent a year in New Britain, Papua New Guinea, which awakened in her a life-long interest in other cultures and in the colonial era.
Clancy gained a Bachelor of Arts and a Bachelor of Social Administration from Flinders University. She worked as a social worker for ten years before moving into the area of project management in information technology.
Clancy's first novel was written while she was on maternity leave at the time of the birth of her daughter Nikita. It followed six years of research which she had done as a hobby. Her second book was written on maternity leave with her second child, Andreas.
Descended from an Irish family from County Clare, Clancy had a longstanding interest in family history and wrote down many of the stories of her pioneering forebears, told her by her great-aunt. The early women had difficult lives, living on properties in the outback and raising large families. Some of the men were bullockies, and Clancy's great-great-grandfather built the poppet head on the Burra copper mine. These areas were used as locations for Clancy's first novel, The Wild Colonial Girl. Scottish ancestry on Clancy's mother's side of the family was the inspiration for Bonnie Douglas, the heroine of Rebel Girl.
Clancy was also co-writer with her husband, Peter Klar, of the business text book Small Business Success: Staying Afloat (1990).