Iona Margaret Balfour Archibald was born in Colchester, Essex, England. She was a researcher and writer on folklore and children's street culture. She is considered an authority on children's rhymes, street and playground games and the Mother Goose tradition. She was elected a Fellow of the British Academy (FBA) in 1998 and was made a Commander of the Order of the British Empire (CBE) in 1999.
The couple met during World War II and married on 2 September 1943. The couple worked together closely, from their home near Farnham, Surrey, conducting primary fieldwork, library research, and interviews of thousands of children. In pursuing the folklore of contemporary childhood they directly recorded rhymes and games in real time as they were being sung, chanted, or played. Working from their home in Alton, Hampshire they collaborated on several celebrated books and produced over 30 works. The couple were jointly awarded the Coote Lake Medal in 1960. The medal is awarded by The Folklore Society "for outstanding research and scholarship".
Speaking in 2010, Iona speaks of working with her husband as being "like two of us in a very small boat and each had an oar and we were trying to row across the Atlantic." and that "[W]e would never discuss ideas verbally except very late at night."
Iona Opie died in 2017.