Marie-Louise Ayres was born in Perth, Western Australia, but has lived most of her life in Canberra, Australian Capital Territory. She completed a doctorate on Australian women's poetry at the Australian National University in 1994. In the same year, she became Curator of the substantial collection of Australian literary manuscripts held by the University of New South Wales at the Australian Defence Force Academy Library. In 1996, Ayres also became responsible for the former AUSTLIT database, and was the inaugural Executive Manager of AustLit: The Australian Literature Resource from the first planning meeting of its contributors in late 1998. In 1999 she was the recipient of a University of New South Wales Travelling Fellowship enabling travel to the UK, USA and Ireland.
In 2002 Ayres took up a position at the National Library of Australia as project manager for Music Australia. She then moved into Manuscripts at the National Library becoming Curator of Manuscripts in 2006. She was subsequently appointed Assistant Director-General, Resource Sharing.
Ayres has published articles on Australian poetry and manuscripts, and on the project management and technical solutions underlying AustLit. In 2007, she was awarded the Friends of the National Library Travelling Fellowship and travelled to the USA and Canada.